Transmission method, device, system, and computer-readable storage medium

ABSTRACT

Provided are a transmission method, apparatus and system and a computer-readable storage medium. The transmission method includes creating an automatic repeat request process for a first packet; setting a lifetime for the automatic repeat request process; and sending the first packet. The lifetime is set for the automatic repeat request process so that the automatic repeat request process can be removed in time. In this manner, in the case where a limited number of automatic repeat request processes are simultaneously supported, a new automatic repeat request process can be created for a newly transmitted packet in time, and thus the transmission efficiency is improved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a National Stage Application filed under 35 U.S.C. 371 based onInternational Patent Application No. PCT/CN2019/110574, filed on Oct.11, 2019, which claims priority to Chinese Patent Application No.201811221633.X filed on Oct. 19, 2018, disclosures of both of which areincorporated herein by reference in their entireties.

TECHNICAL FIELD

Embodiments of the present disclosure relate to a transmission method,apparatus and system and a computer-readable storage medium.

BACKGROUND

With the development of wireless network technology, network performanceis constantly improved. Meanwhile, the requirements for transmissionreliability are increasingly high, and edge users are supported.

In a wireless network operating in an unlicensed frequency band, theprinciple of Listen Before Talk (LBT) needs to be followed. That is, adevice needs to listen to a channel before access and needs to delayaccess to a propagation medium if the device detects that another deviceis performing transmission.

In a wireless local area network, for example, a wireless local areanetwork operating in an unlicensed frequency band, common devices arestations (STAs) including access points (APs) and non-access points(non-APs). Multiple APs form one basic service set (BSS). A non-APassociates with an AP through a scanning, authentication and associationprocess. The non-AP communicates with the AP or communicates with otherSTAs through the AP. In another type of wireless local area network, forexample, an independent BSS (MSS), there is no AP-like access point, andall stations can communicate with each other directly. Regardless of thetype of a wireless local area network, a station needs to access apropagation medium by contending for a channel. Moreover, the packetacknowledgment mechanism currently used in a wireless local area networkis as follows: A sender sends a packet. The packet carries a responsepolicy. The response policy is used for indicating whether a receiverneeds to return a correctness acknowledgment frame. In the case where itis indicated that the receiver needs to return a correctnessacknowledgment frame, the receiver receives the packet, and whendetermining that the reception is incorrect, the receiver does not makeany response and discards the packet. The discarded packet stillcontains valid information. In order for the valid information to beused, an automatic repeat request mechanism is introduced to thewireless local area network. That is, when it is determined that thereceived packet is incorrect, the receiver buffers the packet and usesthe packet for combination processing, and the sender retransmits thepacket or a different redundancy version of the packet.

In a wireless network operating in an unlicensed frequency band, in theprocess of executing an automatic repeat request mechanism, a senderneeds to listen to a channel first each time a packet is retransmittedor a different redundancy version of the packet is retransmitted. Due tofactors such as uncertainty of an access time, an automatic repeatrequest process corresponding to the packet occupies correspondingmanagement and storage resources too long a time. Moreover, the maximumnumber of automatic repeat request processes concurrently supported by adevice is limited by the capability of the device. As a result, ifresources are not released in time, a new automatic repeat requestprocess cannot be created. Thus, the transmission efficiency is reduced.

SUMMARY

Embodiments of the present disclosure provide a transmission method,apparatus and system and a computer-readable storage medium.

In a first aspect, an embodiment of the present disclosure provides atransmission method.

The transmission method includes creating an automatic repeat requestprocess for a first packet; setting a lifetime for the automatic repeatrequest process; and sending the first packet.

In a second aspect, an embodiment of the present disclosure provides atransmission method.

The transmission method includes receiving a packet; and in response todetermining that reception of the packet is incorrect, maintaining thelifetime of a first automatic retransmission buffer block correspondingto the packet.

In a third aspect, an embodiment of the present disclosure provides atransmission apparatus.

The transmission apparatus includes:

a creation module configured to create an automatic repeat requestprocess for a first packet, set a lifetime for the automatic repeatrequest process and send the first packet.

In a fourth aspect, an embodiment of the present disclosure provides atransmission apparatus.

The transmission apparatus includes:

a first receiving module configured to receive a packet; and

a first maintenance module configured to: in response to determiningthat reception of the packet is incorrect and obtaining a firstpredetermined number carried in the packet, maintain the lifetime of anautomatic repeat request process corresponding to the firstpredetermined number.

In a fifth aspect, an embodiment of the present disclosure provides atransmission apparatus.

The transmission apparatus includes:

a second receiving module configured to receive a packet; and

a second maintenance module configured to: in response to determiningthat reception of the packet is incorrect, maintain the lifetime of afirst automatic retransmission buffer block corresponding to the packet.

In a sixth aspect, an embodiment of the present disclosure provides atransmission apparatus. The transmission apparatus includes a processorand a computer-readable storage medium storing instructions. Theprocessor executes the instructions to perform any precedingtransmission method.

In a seventh aspect, an embodiment of the present disclosure provides acomputer-readable storage medium storing a computer program. When thecomputer program is executed by a processor, any preceding transmissionmethod is performed.

In an eighth aspect, an embodiment of the present disclosure provides atransmission system.

The transmission system includes:

a first sender configured to: create an automatic repeat request processfor a first packet, set a lifetime for the automatic repeat requestprocess and send the first packet; and

a first receiver configured to: receive a packet and in response todetermining that reception of the packet is incorrect and obtaining afirst predetermined number carried in the packet, maintain the lifetimeof an automatic repeat request process corresponding to the firstpredetermined number.

In a ninth aspect, an embodiment of the present disclosure provides atransmission system.

The transmission system includes:

a second sender configured to: create an automatic repeat requestprocess for a first packet, set a lifetime for the automatic repeatrequest process and send the first packet; and

a second receiver configured to: receive a packet, and in response todetermining that reception of the packet is incorrect, maintain thelifetime of a first automatic retransmission buffer block correspondingto the packet.

BRIEF DESCRIPTION OF DRAWINGS

The drawings are intended to provide a further understanding ofsolutions of embodiments of the present disclosure, constitute a part ofthe description, illustrate solutions of embodiments of the presentdisclosure in conjunction with embodiments of the present application,and do not limit solutions of embodiments of the present disclosure.

FIG. 1 is a flowchart of a transmission method according to anembodiment of the present disclosure.

FIG. 2 is a flowchart of a transmission method according to anotherembodiment of the present disclosure.

FIG. 3 is a schematic diagram of an automatic retransmission bufferaccording to an embodiment of the present disclosure.

FIG. 4 is a flowchart of a transmission method according to anotherembodiment of the present disclosure.

FIG. 5 is schematic diagram one illustrating frame interaction accordingto an embodiment of the present disclosure.

FIG. 6 is schematic diagram two illustrating frame interaction accordingto an embodiment of the present disclosure.

FIG. 7 is a schematic diagram illustrating a structure of a transmissionapparatus according to another embodiment of the present disclosure.

FIG. 8 is a schematic diagram illustrating a structure of a transmissionapparatus according to another embodiment of the present disclosure.

FIG. 9 is a schematic diagram illustrating a structure of a transmissionapparatus according to another embodiment of the present disclosure.

FIG. 10 is a schematic diagram illustrating a structure of atransmission system according to another embodiment of the presentdisclosure.

FIG. 11 is a schematic diagram illustrating a structure of atransmission system according to another embodiment of the presentdisclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described in detailhereinafter in conjunction with the drawings. It is to be noted that ifnot in collision, the embodiments and features therein in the presentdisclosure may be combined with each other.

The steps illustrated in the flowcharts among the drawings may beperformed by, for example, a computer system capable of executing a setof computer-executable instructions. Moreover, although logicalsequences are illustrated in the flowcharts, the illustrated ordescribed steps may be performed in sequences different from thosedescribed herein in some cases.

Referring to FIG. 1 , an embodiment of the present disclosure provides atransmission method. The transmission method includes step 100.

In step 100, an automatic repeat request process is created for a firstpacket; a lifetime is set for the automatic repeat request process; andthe first packet is sent.

In this embodiment of the present disclosure, the automatic repeatrequest process may be created for the first packet before, when orafter the first packet is sent. That is, the time when the automaticrepeat request process of the first packet is created is acceptable aslong as the absolute value of the difference between the time when thefirst packet is sent and the time when the automatic repeat requestprocess of the first packet is created is within a predetermined timethreshold.

In this embodiment of the present disclosure, the first packet may be anewly transmitted packet or a retransmitted packet, which is not limitedin this embodiment of the present disclosure.

In another embodiment of the present disclosure, the method furtherincludes step 101.

In step 101, the lifetime of the automatic repeat request process startsto be maintained.

In this embodiment of the present disclosure, the lifetime of theautomatic repeat request process may be maintained through a timer or acounter.

In some embodiments of the present disclosure, the lifetime includes atleast one of: a time length, an end time instant of the lifetime, or anumber of times.

In some embodiments of the present disclosure, the time length includesone of: an effective-time length or a remaining-time length.

In some embodiments of the present disclosure, the number of timesincludes one of: a total number of times of a newly transmitted packetand a retransmitted packet carrying the same first predetermined numberas the newly transmitted packet, a total number of remaining times ofthe newly transmitted packet and the retransmitted packet carrying thesame first predetermined number as the newly transmitted packet, a totalnumber of times of the retransmitted packet, or a total number ofremaining times of the retransmitted packet.

The effective-time length refers to a time interval from the time whenthe automatic repeat request process is created or configured to thetime when the automatic repeat request process is removed.

The remaining-time length refers to a time interval from the currenttime to the time when the automatic repeat request process is removed.

The end time instant of the lifetime refers to a time instant when theautomatic repeat request process is removed.

In some embodiments of the present disclosure, when the lifetime is theeffective-time length or the remaining-time length, the lifetime ofautomatic repeat request process can be maintained through a timer,specifically through a timing manner or a countdown timing manner.

When the lifetime is the total number of times of the newly transmittedpacket and the retransmitted packet, the total number of remaining timesof the newly transmitted packet and the retransmitted packet, the totalnumber of times of the retransmitted packet, or the number of remainingtimes of the retransmitted packet, the lifetime of automatic repeatrequest process can be maintained through a counter, specificallythrough a counting manner or a backward counting manner.

In this embodiment of the present disclosure, the time instant when thelifetime of the automatic repeat request process starts to be maintainedis not limited. For example, the lifetime of the automatic repeatrequest process may start to be maintained when the lifetime of theautomatic repeat request process is set.

In some embodiments of the present disclosure, the lifetime is obtainedin one of the manners below.

In a first manner, the lifetime is obtained according to a secondpredetermined number of the packet and a mapping relationship betweenthe lifetime and the second predetermined number of the packet.

In a second manner, the lifetime is obtained according to the secondpredetermined number of the packet and a mapping between the secondpredetermined number of the packet and one of the end time of thelifetime, a remaining-time length, or the number of remaining times.

In a third manner, the lifetime is obtained according to a notifiedlifetime.

In a fourth manner, the lifetime is obtained according to a negotiatedlifetime.

In a fifth manner, the lifetime is obtained according to a presetlifetime.

In some embodiments of the present disclosure, the second predeterminednumber may be a redundancy version number.

In another embodiment of the present disclosure, the method furtherincludes step 102.

In step 102, in response to satisfying a preset retransmission conditionin the lifetime of the automatic repeat request process, a second packetis retransmitted, where the first packet and the second packet carry asame first predetermined number.

In some embodiments of the present disclosure, in the process ofdetermining whether the preset retransmission condition is satisfied inthe lifetime of the automatic repeat request process and the process ofretransmitting the second packet, the lifetime of the automatic repeatrequest process continues being maintained.

In some embodiments of the present disclosure, the first predeterminednumber includes at least one of a process number or a packet number.

In this embodiment of the present disclosure, the preset retransmissioncondition includes at least one of the conditions below.

1. An incorrect-reception acknowledgement frame returned by a receiveris received.

2. The time instant when a channel is obtained through a contentionaccess mechanism is within the lifetime of the automatic repeat requestprocess.

3. All time instants in a first predetermined time interval after theincorrect-reception acknowledgement frame returned by the receiver isreceived are in the lifetime of the automatic repeat request process.

4. An acknowledgement frame returned by the receiver is not received ina second predetermined time interval. The acknowledgement frame includesa correct-reception acknowledgement frame or an incorrect-receptionacknowledgement frame.

When the incorrect-reception acknowledgement frame returned by thereceiver is received, the second packet may be retransmitted using oneof the methods below.

In a first method, the second packet is retransmitted following thefirst predetermined time interval (for example, Short Interframe Space(SIFS)) after the incorrect-reception acknowledgement frame returned bythe receiver is received.

In this method, all time instants in a first predetermined time intervalafter the incorrect-reception acknowledgement frame returned by thereceiver is received are within the lifetime of the automatic repeatrequest process by default. Therefore, it is considered that thelifetime does not expire after the first predetermined time interval,and the second packet can be retransmitted after the first predeterminedtime interval.

In a second method, the second packet is retransmitted after theincorrect-reception acknowledgement frame returned by the receiver isreceived, within the lifetime, and when the channel is obtained throughthe contention access mechanism.

In a third method, when all time instants within the first predeterminedtime interval after the incorrect-reception acknowledgement framereturned by the receiver is received are in the lifetime of theautomatic repeat request process, the second packet is retransmittedafter the first predetermined time interval after theincorrect-reception acknowledgement frame returned by the receiver isreceived; when some or all of the time instant within the firstpredetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received are beyondthe lifetime of the automatic repeat request process, the lifetime ofthe automatic repeat request process is extended to a thirdpredetermined time interval that is after the first predetermined timeinterval after the incorrect-reception acknowledgement frame returned bythe receiver is received. The third predetermined time interval is atleast a time required period for retransmitting the second packet. Thesecond packet is retransmitted after the first predetermined timeinterval after the incorrect-reception acknowledgement frame returned bythe receiver is received.

In a fourth method, when all time instants within the firstpredetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received are withinthe lifetime of the automatic repeat request process, the second packetis retransmitted after the first predetermined time interval after theincorrect-reception acknowledgement frame returned by the receiver isreceived; when some or all of the time instants within the firstpredetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received are beyondthe lifetime of the automatic repeat request process, the automaticrepeat request process is removed when the lifetime of the automaticrepeat request process expires, that is, the second packet is no longerretransmitted after the first predetermined time interval after theincorrect-reception acknowledgement frame returned by the receiver isreceived.

In some embodiments of the present disclosure, the first packet or thesecond packet further carries at least one of: a lifetime, an end timeinstant of the lifetime, a remaining-time length, or a number ofremaining times.

In some embodiments of the present disclosure, the second packet is thesame as the first packet, or the redundancy version of the second packetis different from the redundancy version of the first packet.

In another embodiment of the present disclosure, the method furtherincludes step 103.

In step 103, the automatic repeat request process is removed or endedwhen the lifetime of the automatic repeat request process expires or acorrect-reception acknowledgement frame returned by a receiver isreceived.

In another embodiment of the present disclosure, when the lifetime is atime length and the lifetime is maintained by timing, expiration of thelifetime means that the timer reaches the time length indicted by thelifetime.

When the lifetime is the end time instant and the lifetime is maintainedby a timing manner, expiration of the lifetime means that the timerreaches the end time instant.

When the lifetime is the number of times and the lifetime is maintainedby a counting manner, expiration of the lifetime means that the counterreaches the number of times indicted by the lifetime.

When the lifetime is the time length and the number of times and thelifetime is maintained by a timing and counting manner, expiration ofthe lifetime means that one of the following conditions is satisfied:The timer reaches the time length indicted by the lifetime, or thecounter reaches the number of times indicted by the lifetime.

When the lifetime is the end time and the number of times and thelifetime is maintained by timing and counting, expiration of thelifetime means that one of the following conditions is satisfied: thetimer reaches the end time of the lifetime, or the counter reaches thenumber of times indicted by the lifetime.

When the lifetime is maintained by a countdown timing manner, expirationof the lifetime means that the timer reaches 0.

When the lifetime is maintained by a backward counting manner,expiration of the lifetime means that the counter reaches 0.

When the lifetime is maintained by a countdown timing and backwardcounting manner, expiration of the lifetime means that one of thefollowing conditions is satisfied: the timer reaches 0, or the counterreaches 0.

In some embodiments of the present disclosure, the automatic repeatrequest process is removed or ended in at least one of the states below.

A first state is stopping sending the first packet or stoppingretransmitting the second packet.

A second state is stopping sending a packet carrying the firstpredetermined number.

A third state is stopping sending the first packet or stoppingretransmitting the second packet through an automatic repeat requestmechanism.

In this embodiment of the present disclosure, the automatic repeatrequest process corresponding to the first packet or the second packetis removed or ended when the lifetime of the automatic repeat requestprocess expires or the correct-reception acknowledgement frame returnedby the receiver is received, so that the automatic repeat requestprocess can be removed in time. In this manner, in the case where alimited number of automatic repeat request processes are simultaneouslysupported, a new automatic repeat request process can be created for anewly transmitted packet in time, and thus the transmission efficiencyis improved.

Referring to FIG. 2 , another embodiment of the present disclosureprovides a transmission method. The transmission method includes steps200 and 201.

In step 200, a packet is received.

In step 201, in response to determining that reception of the packet isincorrect and obtaining a first predetermined number carried in thepacket, the lifetime of an automatic repeat request processcorresponding to the first predetermined number is maintained.

In some embodiments of the present disclosure, the first predeterminednumber includes at least one of: a process number or a packet number.

In some embodiments of the present disclosure, when it is determinedthat reception of the packet is incorrect, an incorrect-receptionacknowledgement frame may be returned or no information is returned;when it is determined that reception of the packet is correct, acorrect-reception acknowledgement frame is returned.

In some embodiments of the present disclosure, the lifetime of theautomatic repeat request process corresponding to the firstpredetermined number is maintained in at least one of the manners below.

In a first manner, in response to the received packet satisfying a firstpredetermined condition, the lifetime of the automatic repeat requestprocess corresponding to the first predetermined number starts to bemaintained. When the lifetime of the automatic repeat request process ismaintained through a timer, the timer may be caused to start timing orcountdown timing. When the lifetime of the automatic repeat requestprocess is maintained through a counter, the counter may be caused tostart counting or backward counting.

In a second manner, in response to the received packet satisfying asecond predetermined condition, the lifetime of the automatic repeatrequest process corresponding to the first predetermined numbercontinues being maintained and used. When the lifetime of the automaticrepeat request process is maintained through a timer, the timer may becaused to continue timing or countdown timing or may be caused toperform timing or countdown timing according to a regained lifetime.When the lifetime of the automatic repeat request process is maintainedthrough a counter, the counter may be caused to start counting orbackward counting or may be caused to perform counting or backwardcounting according to a regained lifetime.

In some embodiments of the present disclosure, the first predeterminedcondition includes one of the following: the received packet is a newlytransmitted packet; or the first predetermined number of the receivedpacket is different from first predetermined numbers corresponding toall currently maintained automatic repeat request processes.

In some embodiments of the present disclosure, the second predeterminedcondition includes one of the following: The received packet is aretransmitted packet; or an automatic repeat request process that is thesame as the first predetermined number of the packet exists amongcurrently maintained automatic repeat request processes.

In some embodiments of the present disclosure, whether the receivedpacket is a newly transmitted packet or a retransmitted packet isdetermined in one of the manners below.

In a first manner, it is determined whether the received packet is anewly transmitted packet or a retransmitted packet according tonew-transmission indication information carried in the received packet.In one embodiment, when a newly transmitted packet is indicated in thenew-transmission indication information, it is determined that thereceived packet is a newly transmitted packet; when a retransmittedpacket is indicated in the new-transmission indication information, itis determined that the received packet is a retransmitted packet.

In a second manner, it is determined whether the process number carriedin the packet is the same as the process number corresponding to anautomatic repeat request process which is created or configured. In someembodiments, when the process number carried in the packet is differentfrom the process number corresponding to the automatic repeat requestprocess which is created or configured, it is determined that thereceived packet is a newly transmitted packet; when the process numbercarried in the packet is the same as the process number corresponding tothe automatic repeat request process which is created or configured, itis determined that the received packet is a retransmitted packet.

In a third manner, it is determined whether the packet number carried inthe packet is the same as the packet number corresponding to anautomatic repeat request process which is created or configured. In someembodiments, when the packet number carried in the packet is differentfrom the packet number corresponding to the automatic repeat requestprocess which is created or configured, it is determined that thereceived packet is a newly transmitted packet; when the packet numbercarried in the packet is the same as the packet number corresponding tothe automatic repeat request process which is created or configured, itis determined that the received packet is a retransmitted packet.

In some embodiments of the present disclosure, the lifetime of theautomatic repeat request process may be maintained through a timer or acounter.

In some embodiments of the present disclosure, the lifetime includes atleast one of: a time length, an end time instant of the lifetime, or anumber of times.

In some embodiments of the present disclosure, the time length includesone of: an effective-time length or a remaining-time length.

In some embodiments of the present disclosure, the number of timesincludes one of: a total number of times of a newly transmitted packetand a retransmitted packet carrying the same first predetermined numberas the newly transmitted packet, a total number of remaining times ofthe newly transmitted packet and the retransmitted packet carrying thesame first predetermined number as the newly transmitted packet, a totalnumber of times of the retransmitted packet, or a total number ofremaining times of the retransmitted packet.

The effective-time length refers to a time interval from the time whenthe automatic repeat request process is created or configured to thetime when the automatic repeat request process is removed.

The remaining-time length refers to a time interval from the currenttime to the time when the automatic repeat request process is removed.

The end time instant of the lifetime refers to the time when theautomatic repeat request process is removed.

In some embodiments of the present disclosure, when the lifetime is theeffective-time length or the remaining-time length, the lifetime of theautomatic repeat request process can be maintained through a timer,specifically through by a timing manner or a countdown timing manner.That is, the timer is caused to start timing or countdown timing afterthe automatic repeat request process is created or configured for thereceived packet.

When the lifetime is the total number of times of the newly transmittedpacket and the retransmitted packet, the total number of remaining timesof the newly transmitted packet and the retransmitted packet, the totalnumber of times of the retransmitted packet, or the number of remainingtimes of the retransmitted packet, the lifetime of the automatic repeatrequest process can be maintained through a timer, specifically throughby a timing manner or a countdown timing manner. That is, the counter iscaused to start counting or backward counting after the automatic repeatrequest process is created or configured for the received packet.

In this embodiment of the present disclosure, the lifetime is obtainedin one of the manners below.

In a first manner, the lifetime is obtained according to a secondpredetermined number of the packet and a mapping between the lifetimeand the second predetermined number of the packet.

In a second manner, the lifetime is obtained according to the secondpredetermined number of the packet and a mapping relationship betweenthe second predetermined number of the packet and one of: the end timeinstant of the lifetime, the remaining-time length, or the number ofremaining times.

In a third manner, the lifetime is obtained according to a lifetimecarried in the packet.

In a fourth manner, the lifetime is obtained according to a notifiedlifetime.

In a fifth manner, the lifetime is obtained according to a negotiatedlifetime.

In a sixth manner, the lifetime is obtained according to a presetlifetime.

In some embodiments of the present disclosure, the second predeterminednumber may be a redundancy version number.

In another embodiment of the present disclosure, the packet is discardedwhen it is determined that reception of the packet is incorrect, thereceived packet is a newly transmitted packet, and the firstpredetermined number carried in the packet cannot be obtained, or whenit is determined that reception of the packet is incorrect, the receivedpacket is a retransmitted packet, and the first predetermined numbercarried in the packet cannot be obtained.

In another embodiment of the present disclosure, the method furtherincludes step 202.

In step 202, the automatic repeat request process is removed or endedwhen the lifetime of the automatic repeat request process expires.

In another embodiment of the present disclosure, when the lifetime is atime length and the lifetime is maintained by timing, expiration of thelifetime means that the timer reaches the time length indicted by thelifetime.

When the lifetime is an end time instant and the lifetime is maintainedby a timing manner, expiration of the lifetime means that the timerreaches the end time.

When the lifetime is the number of times and the lifetime is maintainedby a counting manner, expiration of the lifetime means that the counterreaches the number of times indicted by the lifetime.

When the lifetime is the time length and the number of times and thelifetime is maintained by a timing and counting manner, expiration ofthe lifetime means that one of the following conditions is satisfied:the timer reaches the time length indicted by the lifetime, or thecounter reaches the number of times indicted by the lifetime.

When the lifetime is the end time and the number of times and thelifetime is maintained by a timing and counting manner, expiration ofthe lifetime means that one of the following conditions is satisfied:the timer reaches the end time of the lifetime, or the counter reachesthe number of times indicted by the lifetime.

When the lifetime is maintained by a countdown timing manner, expirationof the lifetime means that the timer reaches 0.

When the lifetime is maintained by a backward counting manner,expiration of the lifetime means that the counter reaches 0.

When the lifetime is maintained by a countdown timing and backwardcounting manner, expiration of the lifetime means that one of thefollowing conditions is satisfied: the timer reaches 0, or the counterreaches 0.

In this embodiment of the present disclosure, the automatic repeatrequest process corresponding to the first packet or the second packetis removed or ended when the lifetime of the automatic repeat requestprocess expires, so that the automatic repeat request process can beremoved in time. In this manner, in the case where a limited number ofautomatic repeat request processes are simultaneously supported, a newautomatic repeat request process can be created for a newly transmittedpacket in time, and thus the transmission efficiency is improved.

Referring to FIG. 4 , another embodiment of the present disclosureprovides a transmission method. The transmission method includes steps400 and 401.

In step 400, a packet is received.

In step 401, in response to determining that reception of the packet isincorrect, the lifetime of a first automatic retransmission buffer blockcorresponding to the packet is maintained.

In another embodiment of the present disclosure, it is feasible tobuffer the received packet in the first automatic retransmission bufferblock, or it is feasible to combine the received packet with a packetbuffered in the first automatic retransmission buffer block and thenbuffer the combined packet in the first automatic retransmission bufferblock.

In some embodiments of the present disclosure, when it is determinedthat reception of the packet is incorrect, an incorrect-receptionacknowledgement frame may be returned or no information is returned;when it is determined that reception of the packet is correct, acorrect-reception acknowledgement frame is returned.

In some embodiments of the present disclosure, the lifetime of the firstautomatic retransmission buffer block corresponding to the packet ismaintained in at least one of the manners below.

In response to the packet satisfying a third predetermined condition,the lifetime of the first automatic retransmission buffer blockcorresponding to the packet starts to be maintained.

In response to the packet satisfying a fourth predetermined condition,the lifetime of the first automatic retransmission buffer blockcorresponding to the packet continues being maintained.

In response to the packet satisfying the third predetermined condition,the method further includes configuring the lifetime of the firstautomatic retransmission buffer block for the packet.

In some embodiments of the present disclosure, the third predeterminednumber includes one of the conditions below.

1. A newly transmitted packet is indicated in new-transmissionindication information carried in the packet.

2. A third predetermined number carried in the packet is different fromthird predetermined numbers carried in packets buffered in all automaticretransmission buffer blocks in an automatic retransmission buffer.

In this embodiment of the present disclosure, the case where the thirdpredetermined number carried in the packet is different from thirdpredetermined numbers carried in packets buffered in all automaticretransmission buffer blocks in the automatic retransmission buffer mayinclude the two cases below.

1. The received packet is a newly transmitted packet.

2. The received packet is a retransmitted packet, but the lifetime ofthe automatic retransmission buffer block maintained before the packethas ended, that is, the automatic retransmission buffer block has beencleared or overridden.

In some embodiments of the present disclosure, the fourth predeterminednumber includes one of the conditions below.

1. A retransmitted packet is indicated in new-transmission indicationinformation carried in the packet.

2. A second automatic retransmission buffer block exists in theautomatic retransmission buffer.

In some embodiments of the present disclosure, a third predeterminednumber carried in a packet buffered in the second automaticretransmission buffer block is the same as a third predetermined numbercarried in the received packet.

In some embodiments of the present disclosure, the third predeterminednumber includes one of: a packet number or an identifier for a stationsending the packet.

In some embodiments of the present disclosure, the identifier for thestation includes one of: an association identifier, a partialassociation identifier, or a media access control (MAC) address.

In some embodiments of the present disclosure, the partial associationidentifier may be a part of the association identifier or may becalculated from the association identifier.

In some embodiments of the present disclosure, the lifetime of anautomatic retransmission buffer block may be maintained by a timingmanner or a countdown timing manner.

In some embodiments of the present disclosure, whether the receivedpacket is a newly transmitted packet or a retransmitted packet isdetermined in one of the manners below.

In a first manner, it is determined whether the received packet is anewly transmitted packet or a retransmitted packet according tonew-transmission indication information carried in the received packet.In one embodiment, when a newly transmitted packet is indicated in thenew-transmission indication information, it is determined that thereceived packet is a newly transmitted packet; when a retransmittedpacket is indicated in the new-transmission indication information, itis determined that the received packet is a retransmitted packet.

In a second manner, it is determined whether the third predeterminednumber carried in the received packet is the same as third predeterminednumbers carried in packets buffered in automatic retransmission bufferblocks. In some embodiments, when the third predetermined number carriedin the packet is different from third predetermined numbers carried inpackets buffered in all automatic retransmission buffer blocks, it isdetermined that the received packet is a newly transmitted packet; whena second automatic retransmission buffer block exists in the automaticretransmission buffer, it is determined that the received packet is aretransmitted packet.

In another embodiment of the present disclosure, the method furtherincludes step 402.

In step 402, the first automatic retransmission buffer blockcorresponding to the packet is cleared or overridden when the lifetimeof the first automatic retransmission buffer block corresponding to thepacket expires.

In this embodiment of the present disclosure, an automaticretransmission buffer block is cleared or overridden when the lifetimeof the automatic retransmission buffer block expires so that theautomatic retransmission buffer block is released in time. In thismanner, in the case where there are a limited number of automaticretransmission buffer blocks, a new packet can be buffered in time, andthus the transmission efficiency is improved.

Embodiment One

An intra-BSS station may support one or more automatic repeat requestprocesses simultaneously.

The station maintains one lifetime for each automatic repeat requestprocess. The lifetimes of different automatic repeat request processesmay be the same or different.

In some embodiments of the present disclosure, the lifetime may be aneffective-time length T, that is, a time interval from the time when theautomatic repeat request process is created or configured to the timewhen the automatic repeat request process is removed. T may be a valuenotified by an access point, a value negotiated between a non-accesspoint and the access point, a value determined by the non-access point,or a value predefined by a system.

The station may maintain the lifetime by a timing manner or a countdowntiming manner.

In this embodiment, the station maintains the lifetime by timing, andthe transmission method includes the steps below.

When sender STA1 sends newly transmitted packet 1, STA1 creates orconfigures an automatic repeat request process for packet 1, and timert2 corresponding to the automatic repeat request process starts timing.

Before t2 reaches T, when receiving an incorrect-receptionacknowledgement frame returned by the receiver of packet 1, STA1retransmits packet 1 or retransmits packet 2 in one of the mannersbelow. The redundancy version of packet 2 is different from theredundancy version of packet 1.

In a first manner, packet 1 or packet 2 having a different redundancyversion than packet 1 is retransmitted when a channel is obtainedthrough a contention access mechanism.

In a second manner, packet 1 or packet 2 having a different redundancyversion than packet 1 is retransmitted following a first predeterminedtime interval after the incorrect-reception acknowledgement framereturned by the receiver is received.

In this method, all time instants within the first predetermined timeinterval after the incorrect-reception acknowledgement frame returned bythe receiver of packet 1 is received are within the lifetime of theautomatic repeat request process by default. Therefore, it is consideredthat the lifetime does not expire after the first predetermined timeinterval, and packet 1 or packet 2 having a different redundancy versionthan packet 1 can be retransmitted after the first predetermined timeinterval.

In a third manner, when all time instant within the first predeterminedtime interval after the incorrect-reception acknowledgement framereturned by the receiver is received are within the lifetime of theautomatic repeat request process, packet 1 or packet 2 having adifferent redundancy version than packet 1 is retransmitted after thefirst predetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received; when some orall of the time instants within the first predetermined time intervalafter the incorrect-reception acknowledgement frame returned by thereceiver is received are beyond the lifetime of the automatic repeatrequest process, the lifetime of the automatic repeat request process isextended to a third predetermined time interval that is following thefirst predetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received. The thirdpredetermined time interval is at least a time period required forretransmitting packet 1 or packet 2 having a different redundancyversion than packet 1. Packet 1 or packet 2 having a differentredundancy version than packet 1 is retransmitted after the firstpredetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received.

In the preceding second manner and third manner, the frame interactionprocess is as shown in FIG. 5 .

In a fourth manner, when all time instants within the firstpredetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received are withinthe lifetime of the automatic repeat request process, packet 1 or packet2 having a different redundancy version than packet 1 is retransmittedafter the first predetermined time interval; when some or all of thetime instant within the first predetermined time interval after theincorrect-reception acknowledgement frame returned by the receiver isreceived are beyond the lifetime of the automatic repeat requestprocess, the automatic repeat request process is removed when thelifetime of the automatic repeat request process expires, that is,packet 1 or packet 2 having a different redundancy version than packet 1is no longer retransmitted after the first predetermined time intervalafter the incorrect-reception acknowledgement frame returned by thereceiver is received.

In the preceding method, a packet retransmitted one time may have thesame redundancy version as or a different redundancy version than apacket retransmitted another time.

When one of the conditions below is satisfied, STA1 stops retransmittingpacket 1 or packet 2 having a different redundancy version than packet1.

A. t2 reaches T.

B. The correct-reception acknowledgement frame returned by the receiveris received.

For example, STA1 maintains a lifetime of 100 ms for each automaticrepeat request process, STA1 newly transmits packet 1 to STA2, STA1configures automatic repeat request process 1 for packet 1, andmeanwhile, timer t2 corresponding to automatic repeat request process 1starts timing: t2=0. When receiving an incorrect-receptionacknowledgement frame from STA2, STA1 transmits redundancy version 1 ofpacket 1 after an interval of SIFS. When receiving anincorrect-reception acknowledgement frame from STA2 once again, STA1transmits redundancy version 2 of packet 1 after an interval of SIFS.The rest is done in the same manner until one of the conditions below issatisfied. When one of the conditions below is satisfied, STA1 stopsretransmitting packet 1 or packet 2 having a different redundancyversion than packet 1.

A. t2 reaches 100 ms.

B. The correct-reception acknowledgement frame returned by the receiveris received.

Embodiment Two

An intra-BSS station may support one or more automatic repeat requestprocesses simultaneously.

The station maintains one lifetime for each automatic repeat requestprocess. The lifetimes of different automatic repeat request processesmay be the same or different.

In some embodiments of the present disclosure, the lifetime may be aneffective-time length T. T may be a value notified by an access point, avalue negotiated between a non-access point and the access point, avalue determined by the non-access point, or a value predefined by asystem.

The station may maintain the lifetime by a timing manner or a countdowntiming manner.

In this embodiment, the station maintains the lifetime by timing, andthe transmission method includes the steps below.

When sender STA1 sends newly transmitted packet 1, STA1 creates orconfigures an automatic repeat request process for packet 1, and timert2 corresponding to the automatic repeat request process starts timing.

Before t2 reaches T, when, within a second predetermined time interval,not receiving a correct-reception acknowledgement frame returned by thereceiver of packet 1, STA1 retransmits packet 1 or retransmits packet 2having a different redundancy version than packet 1. If t2 still doesnot reach T, when, within the second predetermined time interval, notreceiving the correct-reception acknowledgement frame returned by thereceiver, STA1 retransmits packet 1 or retransmits packet 2 having adifferent redundancy version than packet 1 and repeats the precedingprocess before t2 reaches T. The frame interaction process is as shownin FIG. 6 .

When one of the conditions below is satisfied, STA1 stops retransmittingpacket 1 or packet 2 having a different redundancy version than packet1.

C. t2 reaches T.

D. The correct-reception acknowledgement frame returned by the receiveris received.

Embodiment Three

An intra-BSS station may support one or more automatic repeat requestprocesses simultaneously.

The station maintains one lifetime for each automatic repeat requestprocess. The lifetimes of different automatic repeat request processesmay be the same or different.

In some embodiments of the present disclosure, the lifetime may be aneffective-time length T. T may be a value notified by an access point, avalue negotiated between a non-access point and the access point, avalue determined by the non-access point, or a value predefined by asystem.

The station may maintain the lifetime by a timing manner or a countdowntiming manner.

In this embodiment, the station maintains the lifetime by timing, andthe transmission method includes the steps below.

Receiver STA2 receives a packet and determines that the packet is anewly transmitted packet received incorrectly. STA2 obtains a firstpredetermined number carried in the packet and starts timer t3 of anautomatic repeat request process corresponding to the firstpredetermined number. When timer t3 reaches T, STA2 removes or ends theautomatic repeat request process. The first predetermined numberincludes at least one of a process number or a packet number.

STA2 determines whether the packet is a newly transmitted packet in, butnot limited to, one of the manners below.

1. It is determined whether the packet is a newly transmitted packetaccording to new-transmission indication information carried in thepacket. When a newly transmitted packet is indicated in thenew-transmission indication information, it is determined that thepacket is a newly transmitted packet; when a retransmitted packet isindicated in the new-transmission indication information, it isdetermined that the packet is a retransmitted packet.

2. It is determined whether the packet is a newly transmitted packetaccording to whether the process number carried in the packet is thesame as the process number corresponding to a created, configured orcurrently maintained automatic repeat request process. When the processnumber carried in the packet is different from the process numbercorresponding to the automatic repeat request process which is created,configured or currently maintained, it is determined that the packet isa newly transmitted packet; when the process number carried in thepacket is the same as the process number corresponding to the automaticrepeat request process which is created, configured or currentlymaintained, it is determined that the packet is a retransmitted packet.

3. It is determined whether the packet is a newly transmitted packetaccording to whether the packet number carried in the packet is the sameas the packet number corresponding to an automatic repeat requestprocess which is created, configured or currently maintained. When thepacket number carried in the packet is different from the packet numbercorresponding to the automatic repeat request process which is created,configured or currently maintained, it is determined that the packet isa newly transmitted packet; when the packet number carried in the packetis the same as the packet number corresponding to the automatic repeatrequest process which is created, configured or currently maintained, itis determined that the packet is a retransmitted packet.

Embodiment Four

An intra-BSS station may support one or more automatic repeat requestprocesses simultaneously.

The station maintains one lifetime for each automatic repeat requestprocess. The lifetimes of different automatic repeat request processesmay be the same or different.

In some embodiments of the present disclosure, a mapping relationshipbetween a lifetime and a second predetermined number include one of:

a mapping relationship is formed between the effective-time length orremaining-time length identifier of the lifetime of an automatic repeatrequest process, the remaining-time length of the lifetime or theeffective-time length of the lifetime of the automatic repeat requestprocess and a second predetermined number; ora mapping relationship is formed between the identifier of the number ofuses of the lifetime of an automatic repeat request process, the totalnumber of times or the number of remaining times of the lifetime and asecond predetermined number.

In some examples, receiver STA2 receives a packet and obtains a secondpredetermined number of the packet; according to a mapping relationshipbetween the predefined second predetermined number and theremaining-time length or the end time instant of the lifetime of anautomatic repeat request process, when the remaining-time length ends orthe end time instant reaches, STA2 removes or ends the automatic repeatrequest process. The remaining-time length or the end time instant ofthe lifetime of the automatic repeat request process may be obtainedaccording to the second predetermined number of the packet.

In other examples, receiver STA2 receives a packet and obtains a secondpredetermined number of the packet; according to a mapping relationshipbetween the predefined second predetermined number and the number ofremaining times of the lifetime of an automatic repeat request process,when the total number of times of the received packet or a packet havinga different redundancy number than the received packet reaches thenumber of remaining times, STA2 removes or ends the automatic repeatrequest process. The number of remaining times of the lifetime of theautomatic repeat request process may be obtained according to the secondpredetermined number of the packet.

For example, a mapping relationship between a second predeterminednumber and the lifetime of an automatic repeat request process is aslisted in Table 1. STA2 receives a packet. STA2 obtains redundancyversion number n2 of the packet. According to the mapping relationshipbetween the second predetermined number and the lifetime of theautomatic repeat request process, STA2 determines that the lifetime ofthe automatic repeat request process is V2. Assuming that aremaining-time length is indicated for the lifetime, STA2 starts timingfrom 0 when receiving the packet and removes or ends the automaticrepeat request process corresponding to the packet when the timerreaches V2.

TABLE 1 Mapping relationship between a second predetermined number andthe lifetime of an automatic repeat request process Second PredeterminedNumber Lifetime n1 V1 n2 V2 n3 V3 . . . . . . nk V4

Embodiment Five

An intra-BSS station may support one or more automatic repeat requestprocesses simultaneously.

The station maintains one lifetime for each automatic repeat requestprocess. The lifetimes of different automatic repeat request processesmay be the same or different.

In some embodiments of the present disclosure, the lifetime may be aneffective-time length T.

In a BSS, a sender or a receiver maintains one timer for each automaticrepeat request process separately.

The transmission method includes the steps below.

When STA1 newly transmits packet 1, STA1 creates or configures anautomatic repeat request process for packet 1 and starts timer t1corresponding to the automatic repeat request process. When t1 reachesT, STA1 removes the automatic repeat request process corresponding topacket 1.

The preceding process includes, but is not limited to the followingoperation: When reception of packet 1 is incorrect while the automaticrepeat request process is being executed, STA1 retransmits packet 1 orpacket 2 having a different redundancy version than packet 1. Packet 2having a different redundancy version than packet 1 and packet 1 havethe same packet number and carry the same valid information butdifferent redundancy information. The valid information is informationbits to be transmitted before coding.

Packet 1 or packet 2 having a different redundancy version than packet 1sent by STA1 in the automatic repeat request process further carry timelength information. The time length information is used for indicatingthe remaining-time length of the lifetime of the automatic repeatrequest process corresponding to packet 1 or packet 2 having a differentredundancy version than packet 1 or indicating the end time of thelifetime of the automatic repeat request process corresponding to packet1 or packet 2 having a different redundancy version than packet 1.

Receiver STA2 can obtain the remaining-time length upon receiving thepreceding packet sent by STA1 or another packet sent by STA1 and havinga different redundancy version than the packet. STA2 removes or ends theautomatic repeat request process when the remaining-time length is 0.

Alternatively, STA2 can obtain the end time of the lifetime of theautomatic repeat request process upon receiving the preceding packetsent by STA1 or another packet sent by STA1 and having a differentredundancy version than the packet. STA2 removes or ends the automaticrepeat request process when the end time comes.

Embodiment Six

An intra-BSS station may support one or more automatic repeat requestprocesses simultaneously.

The station maintains one lifetime for each automatic repeat requestprocess. The lifetimes of different automatic repeat request processesmay be the same or different.

In some embodiments of the present disclosure, the lifetime may be thetotal number of times of a newly transmitted packet and a retransmittedpacket.

In some embodiments of the present disclosure, the newly transmittedpacket and the retransmitted packet of the newly transmitted packet havethe same packet number, carry the same valid information and carry thesame or different redundancy information. The valid information isinformation bits to be transmitted before coding.

For example, as a receiver, STA1 maintains a lifetime of N times foreach automatic repeat request process. That is, the total number oftimes STA1 receives a packet and a retransmitted packet of the packet isN.

STA1 receives a packet and determines whether the packet is a newlytransmitted packet.

A. When it is determined that the packet is a newly transmitted packet,STA1 causes the counter corresponding to the automatic repeat requestprocess corresponding to the first predetermined number of the packet tostart counting.

B. When it is determined that the packet is a non-newly transmittedpacket, STA1 determines whether the packet is the same as the processnumber or the packet number corresponding to a certain current automaticrepeat request process. When the packet is the same as the processnumber or the packet number corresponding to the certain currentautomatic repeat request process, the counter is increased by 1. Whenthe packet is different from the process numbers or the packet numberscorresponding to all current automatic repeat request processes, STA1causes the counter corresponding to the automatic repeat request processcorresponding to the first predetermined number of the packet to startcounting.

When the counter reaches N, STA1 removes the corresponding automaticrepeat request process.

STA1 determines whether the packet is a newly transmitted packet in, butnot limited to, one of the manners below.

1. It is determined whether the packet is a newly transmitted packetaccording to new-transmission indication information carried in thepacket. When a newly transmitted packet is indicated in thenew-transmission indication information, it is determined that thepacket is a newly transmitted packet; when a retransmitted packet isindicated in the new-transmission indication information, it isdetermined that the packet is a retransmitted packet.

2. It is determined whether the process number or the packet numbercarried in the packet is the same as the process number or the packetnumber corresponding to a currently maintained automatic repeat requestprocess. When the process number (or packet number) carried in thepacket is different from the process numbers (or packet numbers)corresponding to all currently maintained automatic repeat requestprocesses, it is determined that the packet is a newly transmittedpacket. When the process number (or packet number) carried in the packetis the same as the process number (or packet number) corresponding to acertain currently maintained automatic repeat request process, it isdetermined that the packet is a retransmitted packet.

Embodiment Seven

An intra-BSS station may support one or more automatic repeat requestprocesses simultaneously. The station maintains one lifetime for eachautomatic repeat request process. The lifetimes of different automaticrepeat request processes may be the same or different.

The lifetime may be the number of remaining times of transmission of apacket and a retransmitted packet of the packet.

In some embodiments of the present disclosure, the packet and theretransmitted packet of the packet carries the same valid informationand the same or different redundancy information. The valid informationis information bits to be transmitted before coding.

For example, sender STA1 carries a lifetime in a sent packet. Thelifetime indicates the number of remaining times of a current packet anda retransmitted packet of the packet. STA1 carries, in a newlytransmitted packet, a lifetime indicating that the number of remainingtimes is N and carries, in a packet transmitted the second time andhaving the same packet number or a retransmitted packet of the packet, alifetime indicating that the number of remaining times is (N−1). In thismanner, STA2 can carry a lifetime in some or all sent packets having thesame packet number or retransmitted packets of the packet.

Receiver STA2 can obtain the lifetime of the automatic repeat requestprocess of a current packet upon receiving one or more of the precedingpackets.

Embodiment Eight

In a wireless network, multiple stations (STAs) form one basic serviceset (BSS).

The general buffer of a station as a receiver contains an automaticretransmission request buffer. The automatic retransmission requestbuffer is divided into one or more automatic retransmission bufferblocks. The station maintains one timer for each automaticretransmission buffer block. The automatic retransmission request bufferis as shown in FIG. 3 .

The station stores packets having the same packet number in the sameautomatic retransmission buffer block and starts timing from the firstpacket having a certain packet number in a certain automaticretransmission buffer block. The longest station-supported duration T ofa buffered packet having the same packet number is T. T denotes thelifetime of a buffered packet corresponding to a certain packet numberin the automatic retransmission buffer block. When T ends, the stationclears or overrides the automatic retransmission buffer block and resetsthe timer corresponding to the automatic retransmission buffer block.

For example, STA1 receives a packet, determines that reception of thepacket is incorrect and learns that the packet number of the packet isM.

A. When it is determined that a current packet is a newly transmittedpacket, an automatic retransmission buffer block denoted by B1 isconfigured for buffering the packet, and timer t1 corresponding to B1starts timing.

B. When it is determined that a current packet is a non-newlytransmitted packet, the packet is buffered in the automaticretransmission buffer block (denoted by B2) corresponding to a packethaving the same packet number M; or the packet is combined with a packetbuffered in B2, and then the combined packet is buffered in B2. B2corresponds to timer t2.

In some embodiments of the present disclosure, STA1 may, but notnecessarily, determine whether a current packet is a newly transmittedpacket according to whether there is an automatic retransmission bufferblock containing a packet having the same packet number as the currentpacket: When no automatic retransmission buffer block containing apacket whose packet number is M is in the automatic retransmissionrequest buffer, it is determined that the current packet is a newlytransmitted packet. When an automatic retransmission buffer blockcontaining a packet whose packet number is M is in the automaticretransmission request buffer, it is determined that the current packetis a non-newly transmitted packet.

When the timer reaches T, STA1 clears the corresponding automaticretransmission buffer block in the automatic retransmission requestbuffer and resets the timer. In this example, when t1 reaches T, STA1clears B1 and resets t1; when t2 reaches T, STA1 clears B2 and resetst2.

When STA1 receives a packet incorrectly, if STA1 does not learn that thepacket number of the packet is M, STA1 discards the packet.

Embodiment Nine

When receiving a packet correctly and learning that the packet number ofthe packet is N, STA1 performs the operations below.

A. When it is determined that the packet is a newly transmitted packet,that is, when no packet whose packet number is N is buffered in theautomatic retransmission request buffer, no operation is performed onthe automatic retransmission request buffer of STA1.

B. When it is determined that the packet is not a newly transmittedpacket, that is, when a packet whose packet number is N is buffered inthe automatic retransmission request buffer, STA1 clears B3 and resetsthe timer corresponding to B3. B3 denotes the automatic retransmissionbuffer block containing the packet whose packet number is N in theautomatic retransmission request buffer.

Embodiment Ten

The general buffer of an intra-BSS station as a receiver contains anautomatic retransmission request buffer. The automatic retransmissionrequest buffer is divided into one or more automatic retransmissionbuffer blocks. The station maintains one timer for each automaticretransmission buffer block.

The station places packets from the same sender in the same bufferblock. The sender is identified by an association identifier, a partialassociation identifier, or a MAC address carried in a packet. Here theassociation identifier, the partial association identifier, or the MACaddress is referred to as a station identifier (STA identifier (SID)).

The station starts timing from the first packet having an SID in acertain automatic retransmission buffer block. The longeststation-supported duration T of a buffered packet having the same SID isT. T denotes the lifetime of a buffered packet corresponding to an SIDin the automatic retransmission buffer block. When T ends, the stationclears or overrides the automatic retransmission buffer block and resetsthe timer corresponding to the automatic retransmission buffer block.

For example, STA1 receives multiple packets from multiple stationssimultaneously. The SIDs of the multiple stations are k1, k2, . . . ,and kn, respectively. STA1 determines whether each packet is receivedcorrectly separately. When a packet is received incorrectly, STA1buffers the incorrectly received packet in the automatic retransmissionbuffer block corresponding to the SID of the station sending the packet.

For example, when receiving a packet sent by the station whose stationidentifier is k1 and determining that reception of the packet isincorrect, STA1 performs the operations below.

A. If no packet from the station identified as k1 is buffered in thecurrent automatic retransmission request buffer, STA1 buffers acurrently received packet in automatic retransmission buffer block Bi,and timer t1 corresponding to Bi starts timing.

B. If a packet from the station identified as k1 is buffered inautomatic retransmission buffer block Bk in the current automaticretransmission request buffer and timer t2 corresponding to Bk does notreach T, STA1 buffers a currently received packet in Bk.

When the timer reaches T, STA1 clears or overrides the correspondingautomatic retransmission buffer block in the automatic retransmissionrequest buffer and resets the timer.

For example, when t1 reaches T, STA1 clears Bi and resets t1.

Embodiment Eleven

The station maintains one lifetime for each automatic repeat requestprocess. The lifetimes of different automatic repeat request processesmay be the same or different.

The lifetime is jointly indicated by time length information and thenumber of times of transmission. That is, the automatic repeat requestprocess is removed or ended when one of the conditions below issatisfied.

1. The timer reaches the end time instant of the lifetime indicated bythe time length information or reaches the calculated end time of thelifetime.

2. The timer reaches the end time instant of the lifetime indicated bythe number of times of transmission or reaches the calculated end timeof the lifetime.

For example, a packet or a different redundancy version of the packetsent by a sender carries lifetime information that includes theremaining-time length T and the number of remaining times oftransmission of a current automatic repeat request process.

A receiver receives the packet, obtains T and N, and performs countingand timing through a counter and a timer respectively. When either thecounter or the timer expires, the receiver removes the automatic repeatrequest process. For example, when the backward counting reaches 0, butthe countdown timing does not reach 0, the receiver removes theautomatic repeat request process. Alternatively, when the countdowntiming reaches 0, but the backward counting does not reach 0, thereceiver removes the automatic repeat request process.

Referring to FIG. 7 , another embodiment of the present disclosureprovides a transmission apparatus. The transmission apparatus includes acreation module 701.

The creation module 701 is configured to create an automatic repeatrequest process for a first packet, set a lifetime for the automaticrepeat request process and send the first packet.

In some embodiments of the present disclosure, the creation module 701may create the automatic repeat request process for the first packetbefore, when or after the first packet is sent. That is, the time whenthe automatic repeat request process of the first packet is created isacceptable as long as the absolute value of the difference between thetime when the first packet is sent and the time when the automaticrepeat request process of the first packet is created is within apredetermined time threshold.

In some embodiments of the present disclosure, the first packet may be anewly transmitted packet or a retransmitted packet. This is not limitedin this embodiment of the present disclosure.

In some embodiments of the present disclosure, the creation module 701is further configured to start to maintain the lifetime of the automaticrepeat request process.

In some embodiments of the present disclosure, the creation module 701may maintain the lifetime of the automatic repeat request processthrough a timer or a counter.

In some embodiments of the present disclosure, the lifetime includes atleast one of: a time length, an end time instant of the lifetime, or anumber of times.

In some embodiments of the present disclosure, the time length includesone of: an effective-time length or a remaining-time length.

In some embodiments of the present disclosure, the number of timesincludes one of: a total number of times of a newly transmitted packetand a retransmitted packet carrying the same first predetermined numberas the newly transmitted packet, a total number of remaining times ofthe newly transmitted packet and the retransmitted packet carrying thesame first predetermined number as the newly transmitted packet, a totalnumber of times of the retransmitted packet, or a number of remainingtimes of the retransmitted packet.

The effective-time length refers to a time interval from the time whenthe automatic repeat request process is created or configured to thetime when the automatic repeat request process is removed.

The remaining-time length refers to a time interval from the currenttime to the time when the automatic repeat request process is removed.

The end time instant of the lifetime refers to the time when theautomatic repeat request process is removed.

In some embodiments of the present disclosure, when the lifetime is theeffective-time length or the remaining-time length, it is feasible tomaintain the lifetime of the automatic repeat request process by timingor countdown timing through a timer.

When the lifetime is the total number of times of the newly transmittedpacket and the retransmitted packet, the total number of remaining timesof the newly transmitted packet and the retransmitted packet, the totalnumber of times of the retransmitted packet, or the number of remainingtimes of the retransmitted packet, it is feasible to maintain thelifetime of the automatic repeat request process by timing or countdowntiming through a timer.

In this embodiment of the present disclosure, the time when the creationmodule 701 starts to maintain the lifetime of the automatic repeatrequest process is not limited. For example, the creation module 701 maystart to maintain the lifetime of the automatic repeat request processwhen the lifetime of the automatic repeat request process is set.

In another embodiment of the present disclosure, the transmissionapparatus further includes a retransmission module 702.

The retransmission module 702 is configured to, in response tosatisfying a preset retransmission condition in the lifetime of theautomatic repeat request process, retransmit a second packet, where thefirst packet and the second packet carry the same first predeterminednumber.

In this embodiment of the present disclosure, in the process in whichthe retransmission module 702 determines whether the presetretransmission condition is satisfied in the lifetime of the automaticrepeat request process and the process in which the retransmissionmodule 702 retransmits the second packet, the creation module 701continues maintaining the lifetime of the automatic repeat requestprocess.

In some embodiments of the present disclosure, the first predeterminednumber includes at least one of: a process number or a packet number.

In this embodiment of the present disclosure, the creation module 701,the retransmission module 702, and a first removal module 703 may obtainthe lifetime in one of the manners below.

In a first manner, the lifetime is obtained according to a secondpredetermined number of the packet and a mapping relationship betweenthe lifetime and the second predetermined number of the packet.

In a second manner, the lifetime is obtained according to the secondpredetermined number of the packet and a mapping between the secondpredetermined number of the packet and one of the end time instant ofthe lifetime, a remaining-time length, or the number of remaining times.

In a third manner, the lifetime is obtained according to a notifiedlifetime.

In a fourth manner, the lifetime is obtained according to a negotiatedlifetime.

In a fifth manner, the lifetime is obtained according to a presetlifetime.

In some embodiments of the present disclosure, the second predeterminednumber may be a redundancy version number.

In this embodiment of the present disclosure, the preset retransmissioncondition includes at least one of the conditions below.

1. An incorrect-reception acknowledgement frame returned by a receiveris received.

2. The time when a channel is obtained through a contention accessmechanism is in the lifetime of the automatic repeat request process.

3. All time instants within a first predetermined time interval afterthe incorrect-reception acknowledgement frame returned by the receiveris received are within the lifetime of the automatic repeat requestprocess.

4. The acknowledgement frame returned by the receiver is not receivedwithin a second predetermined time interval. The acknowledgement frameincludes a correct-reception acknowledgement frame or anincorrect-reception acknowledgement frame.

In some embodiments of the present disclosure, when theincorrect-reception acknowledgement frame returned by the receiver isreceived, the retransmission module 702 may retransmit the second packetusing one of the methods below.

In a first method, the second packet is retransmitted after the firstpredetermined time interval (for example, Short Interframe Space (SIFS))after the incorrect-reception acknowledgement frame returned by thereceiver is received.

In this method, all time instants within a first predetermined timeinterval after the incorrect-reception acknowledgement frame returned bythe receiver is received are in the lifetime of the automatic repeatrequest process by default. Therefore, it is considered that thelifetime does not expire after the first predetermined time interval,and the second packet can be retransmitted after the first predeterminedtime interval.

In a second method, the second packet is retransmitted after theincorrect-reception acknowledgement frame returned by the receiver isreceived, within the lifetime, and when the channel is obtained throughthe contention access mechanism.

In a third method, when all time instants within the first predeterminedtime interval after the incorrect-reception acknowledgement framereturned by the receiver is received are in the lifetime of theautomatic repeat request process, the second packet is retransmittedfollowing the first predetermined time interval after theincorrect-reception acknowledgement frame returned by the receiver isreceived; when some or all of the time instants within the firstpredetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received are beyondthe lifetime of the automatic repeat request process, the lifetime ofthe automatic repeat request process is extended to a thirdpredetermined time interval that is after the first predetermined timeinterval after the incorrect-reception acknowledgement frame returned bythe receiver is received. The third predetermined time interval is atleast a time required for retransmitting the second packet. The secondpacket is retransmitted after the first predetermined time intervalafter the incorrect-reception acknowledgement frame returned by thereceiver is received.

In a fourth method, when all time instants within the firstpredetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received are withinthe lifetime of the automatic repeat request process, the second packetis retransmitted after the first predetermined time interval after theincorrect-reception acknowledgement frame returned by the receiver isreceived; when some or all of the time instants within the firstpredetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received are beyondthe lifetime of the automatic repeat request process, the automaticrepeat request process is removed when the lifetime of the automaticrepeat request process expires, that is, the second packet is no longerretransmitted after the first predetermined time interval after theincorrect-reception acknowledgement frame returned by the receiver isreceived.

In some embodiments of the present disclosure, the first packet or thesecond packet further carries at least one of: a lifetime, an end timeof instant the lifetime, a remaining-time length, or a number ofremaining times.

In some embodiments of the present disclosure, the second packet is thesame as the first packet, or the redundancy version of the second packetis different from the redundancy version of the first packet.

In another embodiment of the present disclosure, the transmissionapparatus further includes a first removal module 703.

The first removal module 703 is configured to remove or end theautomatic repeat request process when the lifetime of the automaticrepeat request process expires or a correct-reception acknowledgementframe returned by a receiver is received.

In another embodiment of the present disclosure, when the lifetime is atime length and the lifetime is maintained by a timing manner,expiration of the lifetime means that the timer reaches the time lengthindicted by the lifetime.

When the lifetime is an end time and the lifetime is maintained by atiming manner, expiration of the lifetime means that the timer reachesthe end time.

When the lifetime is the number of times and the lifetime is maintainedby a counting manner, expiration of the lifetime means that the counterreaches the number of times indicted by the lifetime.

When the lifetime is the time length and the number of times and thelifetime is maintained by a timing and counting manner, expiration ofthe lifetime means that one of the following conditions is satisfied:the timer reaches the time length indicted by the lifetime, or thecounter reaches the number of times indicted by the lifetime.

When the lifetime is the end time instant and the number of times andthe lifetime is maintained by a timing and counting manner, expirationof the lifetime means that one of the following conditions is satisfied:the timer reaches the end time of the lifetime, or the counter reachesthe number of times indicted by the lifetime.

When the lifetime is maintained by a countdown timing manner, expirationof the lifetime means that the timer reaches 0.

When the lifetime is maintained by a backward counting manner,expiration of the lifetime means that the counter reaches 0.

When the lifetime is maintained by a countdown timing and backwardcounting manner, expiration of the lifetime means that one of thefollowing conditions is satisfied: The timer reaches 0, or the counterreaches 0.

In this embodiment of the present disclosure, the first removal module703 is used for removing or ending the automatic repeat request processin at least one of the manners below.

1. The first packet is stopped from being sent or the second packet isstopped from being retransmitted.

2. A packet carrying the first predetermined number is stopped frombeing sent.

3. The first packet is stopped from being sent through an automaticrepeat request mechanism or the second packet is stopped from beingretransmitted through the automatic repeat request mechanism.

In this embodiment of the present disclosure, the automatic repeatrequest process corresponding to the first packet or the second packetis removed or ended when the lifetime of the automatic repeat requestprocess expires or the correct-reception acknowledgement frame returnedby the receiver is received. In this manner, in the case where a limitednumber of automatic repeat request processes are simultaneouslysupported, a new automatic repeat request process can be created for anewly transmitted packet in time, and thus the transmission efficiencyis improved.

Referring to FIG. 8 , another embodiment of the present disclosureprovides a transmission apparatus. The transmission apparatus includes afirst receiving module 801 and a first maintenance module 802.

The first receiving module 801 is configured to receive a packet.

The first maintenance module 802 is configured to, in response todetermining that reception of the packet is incorrect and obtaining afirst predetermined number carried in the packet, maintain the lifetimeof an automatic repeat request process corresponding to the firstpredetermined number.

In another embodiment of the present disclosure, the transmissionapparatus further includes a second removal module 803.

The second removal module 803 is configured to remove or end theautomatic repeat request process when the lifetime of the automaticrepeat request process expires.

In some embodiments of the present disclosure, the first predeterminednumber includes at least one of: a process number or a packet number.

In some embodiments of the present disclosure, when it is determinedthat reception of the packet is incorrect, an incorrect-receptionacknowledgement frame may be returned or no information is returned;when it is determined that reception of the packet is correct, acorrect-reception acknowledgement frame is returned.

In this embodiment of the present disclosure, the first maintenancemodule 802 is configured to maintain the lifetime of the automaticrepeat request process corresponding to the first predetermined numberin at least one of the manners below.

In a first manner, in response to the received packet satisfying a firstpredetermined condition, the lifetime of the automatic repeat requestprocess corresponding to the first predetermined number starts to bemaintained. When the lifetime of the automatic repeat request process ismaintained through a timer, the timer may be caused to start timing orcountdown timing. When the lifetime of the automatic repeat requestprocess is maintained through a counter, the counter may be caused tostart counting or backward counting.

In a second manner, in response to the received packet satisfying asecond predetermined condition, the lifetime of the automatic repeatrequest process corresponding to the first predetermined numbercontinues being maintained and used. When the lifetime of the automaticrepeat request process is maintained through a timer, the timer may becaused to continue timing or countdown timing or may be caused toperform timing or countdown timing according to a regained lifetime.When the lifetime of the automatic repeat request process is maintainedthrough a counter, the counter may be caused to start counting orbackward counting or may be caused to perform counting or backwardcounting according to a regained lifetime.

In some embodiments of the present disclosure, the first predeterminedcondition includes one of the following: The received packet is a newlytransmitted packet; or the first predetermined number of the receivedpacket is different from first predetermined numbers corresponding toall currently maintained automatic repeat request processes.

The second predetermined condition includes one of the following: thereceived packet is a retransmitted packet; or an automatic repeatrequest process that is the same as the first predetermined number ofthe packet exists among currently maintained automatic repeat requestprocesses.

In this embodiment of the present disclosure, the first maintenancemodule 802 is used for determining whether the received packet is anewly transmitted packet or a retransmitted packet in one of the mannersbelow.

In a first manner, it is determined whether the received packet is anewly transmitted packet or a retransmitted packet according tonew-transmission indication information carried in the received packet.In some embodiments, when a newly transmitted packet is indicated in thenew-transmission indication information, it is determined that thereceived packet is a newly transmitted packet; when a retransmittedpacket is indicated in the new-transmission indication information, itis determined that the received packet is a retransmitted packet.

In a second manner, it is determined whether the process number carriedin the packet is the same as the process number corresponding to aautomatic repeat request process which is created or configured. In someembodiments, when the process number carried in the packet is differentfrom the process number corresponding to the automatic repeat requestprocess which is created or configured, it is determined that thereceived packet is a newly transmitted packet; when the process numbercarried in the packet is the same as the process number corresponding tothe automatic repeat request process which is created or configured, itis determined that the received packet is a retransmitted packet.

In a third manner, it is determined whether the packet number carried inthe packet is the same as the packet number corresponding to anautomatic repeat request process which is created or configured. In someembodiments, when the packet number carried in the packet is differentfrom the packet number corresponding to the automatic repeat requestprocess which is created or configured, it is determined that thereceived packet is a newly transmitted packet; when the packet numbercarried in the packet is the same as the packet number corresponding tothe automatic repeat request process which is created or configured, itis determined that the received packet is a retransmitted packet.

In some embodiments of the present disclosure, the first maintenancemodule 802 may maintain the lifetime of the automatic repeat requestprocess through a timer or a counter.

The lifetime includes at least one of: a time length, an end timeinstant of the lifetime, or a number of times.

In some embodiments of the present disclosure, the time length includesone of: an effective-time length or a remaining-time length.

In some embodiments of the present disclosure, the number of timesincludes one of: a total number of times of a newly transmitted packetand a retransmitted packet carrying the same first predetermined numberas the newly transmitted packet, a total number of remaining times ofthe newly transmitted packet and the retransmitted packet carrying thesame first predetermined number as the newly transmitted packet, a totalnumber of times of the retransmitted packet, or a number of remainingtimes of the retransmitted packet.

The effective-time length refers to the time interval from the time whenthe automatic repeat request process is created or configured to thetime when the automatic repeat request process is removed.

The remaining-time length refers to the time interval from the currenttime to the time when the automatic repeat request process is removed.

The end time instant of the lifetime refers to the time when theautomatic repeat request process is removed.

In some embodiments of the present disclosure, when the lifetime is theeffective-time length or the remaining-time length, it is feasible tomaintain the lifetime of the automatic repeat request process by timingor countdown timing through a timer. That is, the timer is caused tostart timing or countdown timing after the automatic repeat requestprocess is created or configured for the received packet.

When the lifetime is the total number of times of the newly transmittedpacket and the retransmitted packet, the total number of remaining timesof the newly transmitted packet and the retransmitted packet, the totalnumber of times of the retransmitted packet, or the number of remainingtimes of the retransmitted packet, it is feasible to maintain thelifetime of the automatic repeat request process by timing or countdowntiming through a timer. That is, the counter is caused to start countingor backward counting after the automatic repeat request process iscreated or configured for the received packet.

In some embodiments of the present disclosure, the first maintenancemodule 802 and the second removal module 803 may obtain the lifetime inone of the manners below.

In a first manner, the lifetime is obtained according to a secondpredetermined number of the packet and a mapping relationship betweenthe lifetime and the second predetermined number of the packet.

In a second manner, the lifetime is obtained according to the secondpredetermined number of the packet and a mapping relationship betweenthe second predetermined number of the packet and one of: an end timeinstant of the lifetime, a remaining-time length, or a number ofremaining times.

In a third manner, the lifetime is obtained according to a lifetimecarried in the packet.

In a fourth manner, the lifetime is obtained according to a notifiedlifetime.

In a fifth manner, the lifetime is obtained according to a negotiatedlifetime.

In a sixth manner, the lifetime is obtained according to a presetlifetime.

In some embodiments of the present disclosure, the second predeterminednumber may be a redundancy version number.

In another embodiment of the present disclosure, when the lifetime is atime length and the lifetime is maintained by timing, expiration of thelifetime means that the timer reaches the time length indicted by thelifetime.

When the lifetime is an end time and the lifetime is maintained by atiming manner, expiration of the lifetime means that the timer reachesthe end time.

When the lifetime is the number of times and the lifetime is maintainedby a counting manner, expiration of the lifetime means that the counterreaches the number of times indicted by the lifetime.

When the lifetime is the time length and the number of times and thelifetime is maintained by a timing and counting manner, expiration ofthe lifetime means that one of the following conditions is satisfied:the timer reaches the time length indicted by the lifetime, or thecounter reaches the number of times indicted by the lifetime.

When the lifetime is the end time and the number of times and thelifetime is maintained by a timing and counting manner, expiration ofthe lifetime means that one of the following conditions is satisfied:the timer reaches the end time of the lifetime, or the counter reachesthe number of times indicted by the lifetime.

When the lifetime is maintained by a countdown timing manner, expirationof the lifetime means that the timer reaches 0.

When the lifetime is maintained by a backward counting manner,expiration of the lifetime means that the counter reaches 0.

When the lifetime is maintained by a countdown timing and backwardcounting manner, expiration of the lifetime means that one of thefollowing conditions is satisfied: the timer reaches 0, or the counterreaches 0.

In another embodiment of the present disclosure, the first maintenancemodule 802 is further used for discarding the packet when it isdetermined that reception of the packet is incorrect, the receivedpacket is a newly transmitted packet, and the first predetermined numbercarried in the packet cannot be obtained; or when it is determined thatreception of the packet is incorrect, the received packet is aretransmitted packet, and the first predetermined number carried in thepacket cannot be obtained.

In this embodiment of the present disclosure, the automatic repeatrequest process corresponding to the first packet or the second packetis removed or ended when the lifetime of the automatic repeat requestprocess expires. In this manner, in the case where a limited number ofautomatic repeat request processes are simultaneously supported, a newautomatic repeat request process can be created for a newly transmittedpacket in time, and thus the transmission efficiency is improved.

Referring to FIG. 9 , another embodiment of the present disclosureprovides a transmission apparatus. The transmission apparatus includes asecond receiving module 901 and a second maintenance module 902.

The second receiving module 901 is configured to receive a packet.

The second maintenance module 902 is configured to, in response todetermining that reception of the packet is incorrect, maintain thelifetime of a first automatic retransmission buffer block correspondingto the packet.

In another embodiment of the present disclosure, the second maintenancemodule 902 is further configured to buffer the received packet in thefirst automatic retransmission buffer block or configured to combine thereceived packet with a packet buffered in the first automaticretransmission buffer block and then buffer the combined packet in thefirst automatic retransmission buffer block.

In this embodiment of the present disclosure, when it is determined thatreception of the packet is incorrect, an incorrect-receptionacknowledgement frame may be returned or no information is returned;when it is determined that reception of the packet is correct, acorrect-reception acknowledgement frame is returned.

In this embodiment of the present disclosure, the second maintenancemodule 902 is configured to maintain the lifetime of the first automaticretransmission buffer block corresponding to the packet in at least oneof the manners below.

In a first manner, in response to the packet satisfying a thirdpredetermined condition, the lifetime of the first automaticretransmission buffer block corresponding to the packet starts to bemaintained.

In a second manner, in response to the packet satisfying a fourthpredetermined condition, the lifetime of the first automaticretransmission buffer block corresponding to the packet continues beingmaintained.

In a third manner, in response to the packet satisfying the thirdpredetermined condition, the method further includes configuring thelifetime of the first automatic retransmission buffer block for thepacket.

In this embodiment of the present disclosure, the third predeterminednumber includes one of the following conditions: A newly transmittedpacket is indicated in new-transmission indication information carriedin the packet; or a third predetermined number carried in the packet isdifferent from third predetermined numbers carried in packets bufferedin all automatic retransmission buffer blocks in an automaticretransmission buffer.

In this embodiment of the present disclosure, the case where the thirdpredetermined number carried in the packet is different from thirdpredetermined numbers carried in packets buffered in all automaticretransmission buffer blocks in the automatic retransmission buffer mayinclude the two cases below.

1. The received packet is a newly transmitted packet.

2. The received packet is a retransmitted packet, but the lifetime ofthe automatic retransmission buffer block maintained before the packethas ended, that is, the automatic retransmission buffer block has beencleared or overridden.

In some embodiments of the present disclosure, the fourth predeterminednumber includes one of the conditions below.

1. A retransmitted packet is indicated in new-transmission indicationinformation carried in the packet.

2. A second automatic retransmission buffer block exists in theautomatic retransmission buffer.

In some embodiments of the present disclosure, a third predeterminednumber carried in a packet buffered in the second automaticretransmission buffer block is the same as a third predetermined numbercarried in the received packet.

In some embodiments of the present disclosure, the third predeterminednumber includes one of a packet number or a identifier for a stationsending the packet.

In some embodiments of the present disclosure, the identifier for astation includes one of an association identifier, a partial associationidentifier, or a MAC address.

In this embodiment of the present disclosure, the second maintenancemodule 902 is configured to determine whether the received packet is anewly transmitted packet or a retransmitted packet in one of the mannersbelow.

In a first manner, it is determined whether the received packet is anewly transmitted packet or a retransmitted packet according tonew-transmission indication information carried in the received packet.In one embodiment, when a newly transmitted packet is indicated in thenew-transmission indication information, it is determined that thereceived packet is a newly transmitted packet; when a retransmittedpacket is indicated in the new-transmission indication information, itis determined that the received packet is a retransmitted packet.

In a second manner, it is determined whether the third predeterminednumber carried in the received packet is the same as third predeterminednumbers carried in packets buffered in automatic retransmission bufferblocks. In some embodiments, when the third predetermined number carriedin the packet is different from third predetermined numbers carried inpackets buffered in all automatic retransmission buffer blocks, it isdetermined that the received packet is a newly transmitted packet; whena second automatic retransmission buffer block exists in the automaticretransmission buffer, it is determined that the received packet is aretransmitted packet.

In this embodiment of the present disclosure, the second maintenancemodule 902 may maintain the lifetime of an automatic retransmissionbuffer block by a timing manner or a countdown timing manner.

In this embodiment of the present disclosure, the transmission apparatusfurther includes a clearing module 903.

The clearing module 903 is configured to clear or override the firstautomatic retransmission buffer block corresponding to the packet whenthe lifetime of the first automatic retransmission buffer blockcorresponding to the packet expires.

In this embodiment of the present disclosure, an automaticretransmission buffer block is cleared or overridden when the lifetimeof the automatic retransmission buffer block expires so that theautomatic retransmission buffer block is released in time. In thismanner, in the case where there are a limited number of automaticretransmission buffer blocks, a new packet can be buffered in time, andthus the transmission efficiency is improved.

Another embodiment of the present disclosure provides a transmissionapparatus. The transmission apparatus includes a processor and acomputer-readable storage medium storing instructions. The processorexecutes the instructions to perform any preceding transmission method.

Another embodiment of the present disclosure provides acomputer-readable storage medium storing a computer program. When thecomputer program is executed by a processor, any preceding transmissionmethod is performed.

Referring to FIG. 10 , another embodiment of the present disclosureprovides a transmission system. The transmission system includes a firstsender 1001 and a first receiver 1002.

The first sender 1001 is configured to create an automatic repeatrequest process for a first packet, set a lifetime for the automaticrepeat request process and send the first packet.

The first receiver 1002 is configured to receive a packet, and inresponse to determining that reception of the packet is incorrect andobtaining a first predetermined number carried in the packet, maintainthe lifetime of an automatic repeat request process corresponding to thefirst predetermined number.

In this embodiment of the present disclosure, the first sender 1001 maycreate the automatic repeat request process for the first packet before,when or after the first packet is sent. That is, the time when the firstsender 1001 creates the automatic repeat request process of the firstpacket is acceptable as long as the absolute value of the differencebetween the time when the first sender 1001 sends the automatic repeatrequest process of the first packet and the time when the first sender1001 creates the automatic repeat request process of the first packet iswithin a predetermined time threshold.

In this embodiment of the present disclosure, the first packet may be anewly transmitted packet or a retransmitted packet. This is not limitedin this embodiment of the present disclosure.

In another embodiment of the present disclosure, the first sender 1001is further configured to start to maintain the lifetime of the automaticrepeat request process.

In this embodiment of the present disclosure, the first sender 1001 andthe first receiver 1002 may maintain the lifetime of the automaticrepeat request process through a timer or a counter.

In some embodiments of the present disclosure, the lifetime includes atleast one of: a time length, an end time instant of the lifetime, or anumber of times.

In some embodiments of the present disclosure, the time length includesone of an effective-time length or a remaining-time length.

In some embodiments of the present disclosure, the number of timesincludes one of: a total number of times of a newly transmitted packetand a retransmitted packet carrying the same first predetermined numberas the newly transmitted packet, a total number of remaining times ofthe newly transmitted packet and the retransmitted packet carrying thesame first predetermined number as the newly transmitted packet, a totalnumber of times of the retransmitted packet, or a number of remainingtimes of the retransmitted packet.

The effective-time length refers to the time interval from the time whenthe automatic repeat request process is created or configured to thetime when the automatic repeat request process is removed.

The remaining-time length refers to the time interval from the currenttime to the time when the automatic repeat request process is removed.

The end time instant of the lifetime refers to the time when theautomatic repeat request process is removed.

In some embodiments of the present disclosure, when the lifetime is theeffective-time length or the remaining-time length, it is feasible tomaintain the lifetime of the automatic repeat request process by timingor countdown timing through a timer.

When the lifetime is the total number of times of the newly transmittedpacket and the retransmitted packet, the total number of remaining timesof the newly transmitted packet and the retransmitted packet, the totalnumber of times of the retransmitted packet, or the number of remainingtimes of the retransmitted packet, it is feasible to maintain thelifetime of the automatic repeat request process by timing or countdowntiming through a timer.

In this embodiment of the present disclosure, the time when the lifetimeof the automatic repeat request process starts to be maintained is notlimited. For example, the lifetime of the automatic repeat requestprocess may start to be maintained when the lifetime of the automaticrepeat request process is set.

In this embodiment of the present disclosure, the first sender 1001 mayobtain the lifetime in one of the manners below.

In a first manner, the lifetime is obtained according to a secondpredetermined number of the packet and a mapping relationship betweenthe lifetime and the second predetermined number of the packet.

In a second manner, the lifetime is obtained according to the secondpredetermined number of the packet and a mapping relationship betweenthe second predetermined number of the packet and one of the end timeinstant of the lifetime, a remaining-time length, or the number ofremaining times.

In a third manner, the lifetime is obtained according to a notifiedlifetime.

In a fourth manner, the lifetime is obtained according to a negotiatedlifetime.

In a fifth manner, the lifetime is obtained according to a presetlifetime.

In some embodiments of the present disclosure, the second predeterminednumber may be a redundancy version number.

In another embodiment of the present disclosure, the first sender 1001is further configured to, in response to satisfying a presetretransmission condition in the lifetime of the automatic repeat requestprocess, retransmit a second packet, where the first packet and thesecond packet carry the same first predetermined number.

In this embodiment of the present disclosure, in the process ofdetermining whether the preset retransmission condition is satisfiedwithin the lifetime of the automatic repeat request process and theprocess of retransmitting the second packet, the first sender 1001continues maintaining the lifetime of the automatic repeat requestprocess.

In this embodiment of the present disclosure, the first predeterminednumber includes at least one of: a process number or a packet number.

In this embodiment of the present disclosure, the preset retransmissioncondition includes at least one of the conditions below.

1. An incorrect-reception acknowledgement frame returned by a receiveris received.

2. The time when a channel is obtained through a contention accessmechanism is in the lifetime of the automatic repeat request process.

3. All time instants within a first predetermined time interval afterthe incorrect-reception acknowledgement frame returned by the receiveris received are in the lifetime of the automatic repeat request process.

4. An acknowledgement frame returned by the receiver is not receivedwithin a second predetermined time interval. The acknowledgement frameincludes a correct-reception acknowledgement frame or anincorrect-reception acknowledgement frame.

In some embodiments of the present disclosure, when theincorrect-reception acknowledgement frame returned by the receiver isreceived, the first sender 1001 may retransmit the second packet usingone of the methods below.

In a first method, the second packet is retransmitted after the firstpredetermined time interval (for example, Short Interframe Space (SIFS))after the incorrect-reception acknowledgement frame returned by thereceiver is received.

In this method, all time instants within a first predetermined timeinterval after the incorrect-reception acknowledgement frame returned bythe receiver is received are within the lifetime of the automatic repeatrequest process by default. Therefore, it is considered that thelifetime does not expire after the first predetermined time interval,and the second packet can be retransmitted after the first predeterminedtime interval.

In a second method, the second packet is retransmitted after theincorrect-reception acknowledgement frame returned by the receiver isreceived, within the lifetime, and when the channel is obtained throughthe contention access mechanism.

In a third method, when all time instants within the first predeterminedtime interval after the incorrect-reception acknowledgement framereturned by the receiver is received are within the lifetime of theautomatic repeat request process, the second packet is retransmittedafter the first predetermined time interval after theincorrect-reception acknowledgement frame returned by the receiver isreceived; when some or all of the time instants within the firstpredetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received are beyondthe lifetime of the automatic repeat request process, the lifetime ofthe automatic repeat request process is extended to a thirdpredetermined time interval that is following the first predeterminedtime interval after the incorrect-reception acknowledgement framereturned by the receiver is received. The third predetermined timeinterval is at least a time required for retransmitting the secondpacket. The second packet is retransmitted after the first predeterminedtime interval after the incorrect-reception acknowledgement framereturned by the receiver is received.

In a fourth method, when all time instants within the firstpredetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received are withinthe lifetime of the automatic repeat request process, the second packetis retransmitted after the first predetermined time interval after theincorrect-reception acknowledgement frame returned by the receiver isreceived; when some or all of the time instants within the firstpredetermined time interval after the incorrect-receptionacknowledgement frame returned by the receiver is received are beyondthe lifetime of the automatic repeat request process, the automaticrepeat request process is removed when the lifetime of the automaticrepeat request process expires, that is, the second packet is no longerretransmitted after the first predetermined time interval after theincorrect-reception acknowledgement frame returned by the receiver isreceived.

In this embodiment of the present disclosure, the first packet or thesecond packet further carries at least one of: a lifetime, an end timeinstant of the lifetime, a remaining-time length, or a number ofremaining times.

In some embodiments of the present disclosure, the second packet is thesame as the first packet, or the redundancy version of the second packetis different from the redundancy version of the first packet.

In another embodiment of the present disclosure, the first sender 1001is further configured to remove or end the automatic repeat requestprocess when the lifetime of the automatic repeat request processexpires or a correct-reception acknowledgement frame returned by areceiver is received.

In another embodiment of the present disclosure, when the lifetime is atime length and the lifetime is maintained by timing, expiration of thelifetime means that the timer reaches the time length indicted by thelifetime.

When the lifetime is an end time and the lifetime is maintained by atiming manner, expiration of the lifetime means that the timer reachesthe end time.

When the lifetime is the number of times and the lifetime is maintainedby a counting manner, expiration of the lifetime means that the counterreaches the number of times indicted by the lifetime.

When the lifetime is the time length and the number of times and thelifetime is maintained by a timing and counting manner, expiration ofthe lifetime means that one of the following conditions is satisfied:The timer reaches the time length indicted by the lifetime, or thecounter reaches the number of times indicted by the lifetime.

When the lifetime is the end time and the number of times and thelifetime is maintained by a timing and counting manner, expiration ofthe lifetime means that one of the following conditions is satisfied:The timer reaches the end time of the lifetime, or the counter reachesthe number of times indicted by the lifetime.

When the lifetime is maintained by a countdown timing manner, expirationof the lifetime means that the timer reaches 0.

When the lifetime is maintained by backward counting, expiration of thelifetime means that the counter reaches 0.

When the lifetime is maintained by a countdown timing and backwardcounting manner, expiration of the lifetime means that one of thefollowing conditions is satisfied: The timer reaches 0, or the counterreaches 0.

In this embodiment of the present disclosure, the first sender 1001 isconfigured to remove or end the automatic repeat request process in atleast one of the manners below.

1. The first packet is stopped from being sent or the second packet isstopped from being retransmitted.

2. A packet carrying the first predetermined number is stopped frombeing sent.

3. The first packet is stopped from being sent through an automaticrepeat request mechanism or the second packet is stopped from beingretransmitted through the automatic repeat request mechanism.

In this embodiment of the present disclosure, the automatic repeatrequest process corresponding to the first packet or the second packetis removed or ended when the lifetime of the automatic repeat requestprocess expires or the correct-reception acknowledgement frame returnedby the receiver is received. In this manner, in the case where a limitednumber of automatic repeat request processes are simultaneouslysupported, a new automatic repeat request process can be created for anewly transmitted packet in time, and thus the transmission efficiencyis improved.

In this embodiment of the present disclosure, the first predeterminednumber includes at least one of: a process number or a packet number.

In this embodiment of the present disclosure, when determining thatreception of the packet is incorrect, the first receiver 1002 may returnan incorrect-reception acknowledgement frame or return no information;when determining that reception of the packet is correct, the firstreceiver 1002 may return a correct-reception acknowledgement frame.

In this embodiment of the present disclosure, the first receiver 1002 isconfigured to maintain the lifetime of the automatic repeat requestprocess corresponding to the first predetermined number in at least oneof the manners below.

In a first manner, in response to the received packet satisfying a firstpredetermined condition, the lifetime of the automatic repeat requestprocess corresponding to the first predetermined number starts to bemaintained. When the lifetime of the automatic repeat request process ismaintained through a timer, the timer may be caused to start timing orcountdown timing. When the lifetime of the automatic repeat requestprocess is maintained through a counter, the counter may be caused tostart counting or backward counting.

In a second manner, in response to the received packet satisfying asecond predetermined condition, the lifetime of the automatic repeatrequest process corresponding to the first predetermined numbercontinues being maintained and used. When the lifetime of the automaticrepeat request process is maintained through a timer, the timer may becaused to continue timing or countdown timing or may be caused toperform timing or countdown timing according to a regained lifetime.When the lifetime of the automatic repeat request process is maintainedthrough a counter, the counter may be caused to start counting orbackward counting or may be caused to perform counting or backwardcounting according to a regained lifetime.

In some embodiments of the present disclosure, the first predeterminedcondition includes one of the following: the received packet is a newlytransmitted packet; or the first predetermined number of the receivedpacket is different from first predetermined numbers corresponding toall currently maintained automatic repeat request processes.

The second predetermined condition includes one of the following: thereceived packet is a retransmitted packet; or an automatic repeatrequest process that is the same as the first predetermined number ofthe packet exists among currently maintained automatic repeat requestprocesses.

In some embodiments of the present disclosure, the first receiver 1002may determine whether the received packet is a newly transmitted packetor a retransmitted packet in one of the manners below.

In a first manner, it is determined whether the received packet is anewly transmitted packet or a retransmitted packet according tonew-transmission indication information carried in the received packet.In some embodiments, when a newly transmitted packet is indicated in thenew-transmission indication information, it is determined that thereceived packet is a newly transmitted packet; when a retransmittedpacket is indicated in the new-transmission indication information, itis determined that the received packet is a retransmitted packet.

In a second manner, it is determined whether the process number carriedin the packet is the same as the process number corresponding to acreated or configured automatic repeat request process. In someembodiments, when the process number carried in the packet is differentfrom the process number corresponding to the created or configuredautomatic repeat request process, it is determined that the receivedpacket is a newly transmitted packet; when the process number carried inthe packet is the same as the process number corresponding to thecreated or configured automatic repeat request process, it is determinedthat the received packet is a retransmitted packet.

In a third manner, it is determined whether the packet number carried inthe packet is the same as the packet number corresponding to a createdor configured automatic repeat request process. In some embodiments,when the packet number carried in the packet is different from thepacket number corresponding to the created or configured automaticrepeat request process, it is determined that the received packet is anewly transmitted packet; when the packet number carried in the packetis the same as the packet number corresponding to the created orconfigured automatic repeat request process, it is determined that thereceived packet is a retransmitted packet.

In this embodiment of the present disclosure, the first receiver 1002may obtain the lifetime in one of the manners below.

In a first manner, the lifetime is obtained according to a secondpredetermined number of the packet and a mapping between the lifetimeand the second predetermined number of the packet.

In a second manner, the lifetime is obtained according to the secondpredetermined number of the packet and a mapping relationship betweenthe second predetermined number of the packet and one of an end timeinstant of the lifetime, a remaining-time length, or a number ofremaining times.

In a third manner, the lifetime is obtained according to a lifetimecarried in the packet.

In a fourth manner, the lifetime is obtained according to a notifiedlifetime.

In a fifth manner, the lifetime is obtained according to a negotiatedlifetime.

In a sixth manner, the lifetime is obtained according to a presetlifetime.

In some embodiments of the present disclosure, the second predeterminednumber may be a redundancy version number.

In another embodiment of the present disclosure, the packet is discardedwhen it is determined that reception of the packet is incorrect, thereceived packet is a newly transmitted packet, and the firstpredetermined number carried in the packet cannot be obtained; or whenit is determined that reception of the packet is incorrect, the receivedpacket is a retransmitted packet, and the first predetermined numbercarried in the packet cannot be obtained.

In this embodiment of the present disclosure, the first receiver 1002 isfurther configured to remove or end the automatic repeat request processwhen the lifetime of the automatic repeat request process expires.

In this embodiment of the present disclosure, the automatic repeatrequest process corresponding to the first packet or the second packetis removed or ended when the lifetime of the automatic repeat requestprocess expires. In this manner, in the case where a limited number ofautomatic repeat request processes are simultaneously supported, a newautomatic repeat request process can be created for a newly transmittedpacket in time, and thus the transmission efficiency is improved.

Referring to FIG. 11 , another embodiment of the present disclosureprovides a transmission system. The transmission system includes asecond sender 1101 and a second receiver 1102.

The second sender 1101 is configured to create an automatic repeatrequest process for a first packet, set a lifetime for the automaticrepeat request process and send the first packet.

The second receiver 1102 is configured to receive a packet, and inresponse to determining that reception of the packet is incorrect,maintain the lifetime of a first automatic repeat buffer blockcorresponding to the packet.

In this embodiment of the present disclosure, the implementation processof the second sender 1101 is the same as that of the first sender 1001.The details are not repeated here.

In another embodiment of the present disclosure, the second receiver1102 is further configured to buffer the received packet in the firstautomatic retransmission buffer block or configured to combine thereceived packet with a packet buffered in the first automaticretransmission buffer block and then buffer the combined packet in thefirst automatic retransmission buffer block.

In this embodiment of the present disclosure, when determining thatreception of the packet is incorrect, the second receiver 1102 mayreturn an incorrect-reception acknowledgement frame or return noinformation; when determining that reception of the packet is correct,the second receiver 1102 may return a correct-reception acknowledgementframe.

In this embodiment of the present disclosure, the second receiver 1102is used for maintaining the lifetime of the first automaticretransmission buffer block corresponding to the packet in at least oneof the manners below.

In a first manner, in response to the packet satisfying a thirdpredetermined condition, the lifetime of the first automaticretransmission buffer block corresponding to the packet starts to bemaintained.

In a second manner, in response to the packet satisfying a fourthpredetermined condition, the lifetime of the first automaticretransmission buffer block corresponding to the packet continues beingmaintained.

In a third manner, in response to the packet satisfying the thirdpredetermined condition, the method further includes configuring thelifetime of the first automatic retransmission buffer block for thepacket.

In this embodiment of the present disclosure, the third predeterminednumber includes one of the following conditions: a newly transmittedpacket is indicated in new-transmission indication information carriedin the packet; or a third predetermined number carried in the packet isdifferent from third predetermined numbers carried in packets bufferedin all automatic retransmission buffer blocks in an automaticretransmission buffer.

In this embodiment of the present disclosure, the case where the thirdpredetermined number carried in the packet is different from thirdpredetermined numbers carried in packets buffered in all automaticretransmission buffer blocks in the automatic retransmission buffer mayinclude the two cases below.

1. The received packet is a newly transmitted packet.

2. The received packet is a retransmitted packet, but the lifetime ofthe automatic retransmission buffer block maintained before the packethas ended, that is, the automatic retransmission buffer block has beencleared or overridden.

In this embodiment of the present disclosure, the fourth predeterminednumber includes one of the following conditions: A retransmitted packetis indicated in new-transmission indication information carried in thepacket; or a second automatic retransmission buffer block exists in theautomatic retransmission buffer.

In some embodiments of the present disclosure, a third predeterminednumber carried in a packet buffered in the second automaticretransmission buffer block is the same as a third predetermined numbercarried in the received packet.

In some embodiments of the present disclosure, the third predeterminednumber includes one of a packet number or a identifier for a stationsending the packet.

In some embodiments of the present disclosure, the identifier for astation includes one of: an association identifier, a partialassociation identifier, or a MAC address.

In some embodiments of the present disclosure, the partial associationidentifier may be a part of the association identifier or may becalculated from the association identifier.

In some embodiments of the present disclosure, the lifetime of anautomatic retransmission buffer block may be maintained by timing orcountdown timing.

In this embodiment of the present disclosure, the second receiver 1102may determine whether the received packet is a newly transmitted packetor a retransmitted packet in one of the manners below.

In a first manner, it is determined whether the received packet is anewly transmitted packet or a retransmitted packet according tonew-transmission indication information carried in the received packet.In one embodiment, when a newly transmitted packet is indicated in thenew-transmission indication information, it is determined that thereceived packet is a newly transmitted packet; when a retransmittedpacket is indicated in the new-transmission indication information, itis determined that the received packet is a retransmitted packet.

In a second manner, it is determined whether the third predeterminednumber carried in the received packet is the same as third predeterminednumbers carried in packets buffered in automatic retransmission bufferblocks. In some embodiments, when the third predetermined number carriedin the packet is different from third predetermined numbers carried inpackets buffered in all automatic retransmission buffer blocks, it isdetermined that the received packet is a newly transmitted packet; whena second automatic repeat buffer block exists in the automatic repeatbuffer, it is determined that the received packet is a retransmittedpacket.

In another embodiment of the present disclosure, the second receiver1102 is further configured to clear or override the first automaticrepeat buffer block corresponding to the packet when the lifetime of thefirst automatic repeat buffer block corresponding to the packet expires.

In this embodiment of the present disclosure, an automaticretransmission buffer block is cleared or overridden when the lifetimeof the automatic retransmission buffer block expires so that theautomatic retransmission buffer block is released in time. In thismanner, in the case where there are a limited number of automaticretransmission buffer blocks, a new packet can be buffered in time, andthus the transmission efficiency is improved.

It is to be understood by those having ordinary skill in the art thatsome or all steps of the preceding method and function modules/units inthe preceding system or device may be implemented as software, firmware,hardware and suitable combinations thereof. In the hardwareimplementation, the division of the preceding function modules/units maynot correspond to the division of physical components. For example, onephysical component may have multiple functions, or one function or stepmay be performed jointly by several physical components. Some or allphysical components may be implemented as software executed by aprocessor such as a digital signal processor or a microprocessor, may beimplemented as hardware, or may be implemented as integrated circuitssuch as application-specific integrated circuits. Such software may bedistributed over computer-readable media. The computer-readable mediamay include computer storage media (or non-transitory media) andcommunication media (or transitory media). As is known to those havingordinary skill in the art, the term computer storage media includevolatile and non-volatile as well as removable and non-removable mediaimplemented in any method or technology for storing information (such ascomputer-readable instructions, data structures, program modules orother data). The storage media include, but are not limited to, a RAM, aROM, an EEPROM, a flash memory or other memory technologies, a CD-ROM, aDVD or other optical storages, a magnetic cassette, a magnetic tape, amagnetic disk or other magnetic storage devices, or any other mediumthat can be used for storing desired information and that can beaccessed by a computer. Moreover, as is known to those having ordinaryskill in the art, communication media generally includecomputer-readable instructions, data structures, program modules, orother data in carriers or in modulated data signals transported in othertransport mechanisms and may include any information delivery medium.

The implementations disclosed in embodiments of the present disclosureare intended to facilitate an understanding of embodiments of thepresent disclosure and not to limit embodiments of the presentdisclosure. Any person skilled in the art to which embodiments of thepresent disclosure pertain may make any modifications and changes in theform and details of implementation without departing from the spirit andscope disclosed in embodiments of the present disclosure, but the scopeof the present patent is still subject to the scope defined by theappended claims.

What is claimed is:
 1. A transmission method, comprising: creating anautomatic repeat request process for a first packet; setting a lifetimefor the automatic repeat request process; and sending the first packet;wherein the lifetime is obtained in one of the following manners:obtained according to a second predetermined number of the first packetand a mapping relationship between the lifetime and the secondpredetermined number of the first packet; obtained according to thesecond predetermined number of the first packet and a mappingrelationship between the second predetermined number of the packet andone of an end time instant of the lifetime, a remaining-time length, ora number of remaining times; wherein the second predetermined number isredundancy version number.
 2. The transmission method of claim 1,wherein the lifetime comprises at least one of: a time length, an endtime instant of the lifetime, or a number of times, wherein the timelength comprises one of: an effective-time length or a remaining-timelength; and the number of times comprises one of: a total number oftimes of a newly transmitted packet and a retransmitted packet carryinga same first predetermined number as the newly transmitted packet, atotal number of remaining times of the newly transmitted packet and theretransmitted packet carrying the same first predetermined number as thenewly transmitted packet, a total number of times of the retransmittedpacket, or a number of remaining times of the retransmitted packet;wherein the first predetermined number comprises at least one of aprocess number or a packet number.
 3. The transmission method of claim1, further comprising: keeping the automatic repeat request processuntil the lifetime of the automatic repeat request process expires. 4.The transmission method of claim 3, further comprising: in response tosatisfying a preset retransmission condition in the lifetime of theautomatic repeat request process, retransmitting a second packet,wherein the first packet and the second packet carry a same firstpredetermined number; wherein the first predetermined number comprisesat least one of a process number or a packet number.
 5. The transmissionmethod of claim 1, wherein the first packet or the second packet furthercarries at least one of: the lifetime, an end time instant of thelifetime, a remaining-time length, or a number of remaining times. 6.The transmission method of claim 1, wherein the second packet is thesame as the first packet, or a redundancy version of the second packetis different from a redundancy version of the first packet.
 7. Thetransmission method of claim 1, further comprising: removing or endingthe automatic repeat request process when the lifetime of the automaticrepeat request process expires or a correct-reception acknowledgementframe returned by a receiver is received.
 8. A transmission apparatus,comprising: a processor and a memory storing processor-executableinstructions which, when executed by the processor, are configured toimplement the method of claim
 1. 9. A transmission method, comprising:receiving a packet; and in response to determining that reception of thepacket is incorrect and obtaining a first predetermined number carriedin the packet, maintaining a lifetime of an automatic repeat requestprocess corresponding to the first predetermined number; wherein thelifetime is obtained in one of the following manners: obtained accordingto a second predetermined number of the first packet and a mappingrelationship between the lifetime and the second predetermined number ofthe first packet; obtained according to the second predetermined numberof the first packet and a mapping relationship between the secondpredetermined number of the packet and one of an end time instant of thelifetime, a remaining-time length, or a number of remaining times;wherein the first predetermined number comprises at least one of aprocess number or a packet number and the second predetermined number isredundancy version number.
 10. The transmission method of claim 9,further comprising: removing or ending the automatic repeat requestprocess when the lifetime of the automatic repeat request processexpires.
 11. The transmission method of claim 9, wherein maintaining thelifetime of the automatic repeat request process corresponding to thefirst predetermined number comprises at least one of: in response to thepacket received satisfying a first predetermined condition, starting tomaintain the lifetime of the automatic repeat request processcorresponding to the first predetermined number; or and using thelifetime of the automatic repeat request process corresponding to thefirst predetermined number.
 12. The transmission method of claim 9,wherein the lifetime comprises at least one of: a time length, an endtime instant of the lifetime, or a number of times, wherein the timelength comprises one of an effective-time length or a remaining-timelength; and the number of times comprises one of: a total number oftimes of a newly transmitted packet and a retransmitted packet carryinga same first predetermined number as the newly transmitted packet, atotal number of remaining times of the newly transmitted packet and theretransmitted packet carrying the same first predetermined number as thenewly transmitted packet, a total number of times of the retransmittedpacket, or a number of remaining times of the retransmitted packet. 13.A transmission apparatus, comprising: a processor and a memory storingprocessor-executable instructions which, when executed by the processor,are configured to implement the method of claim
 9. 14. A transmissionmethod, comprising: receiving a packet; and in response to determiningthat reception of the packet is incorrect, maintaining a lifetime of afirst automatic retransmission buffer block corresponding to the packet;wherein the lifetime is obtained in one of the following manners:obtained according to a second predetermined number of the first packetand a mapping relationship between the lifetime and the secondpredetermined number of the first packet; obtained according to thesecond predetermined number of the first packet and a mappingrelationship between the second predetermined number of the packet andone of an end time instant of the lifetime, a remaining-time length, ora number of remaining times; wherein the second predetermined number isredundancy version number.
 15. The transmission method of claim 14,further comprising: clearing or overriding the first automaticretransmission buffer block corresponding to the packet when thelifetime of the first automatic retransmission buffer blockcorresponding to the packet expires.
 16. The transmission method ofclaim 14, wherein maintaining the lifetime of the first automaticretransmission buffer block corresponding to the packet comprises atleast one of: in response to the packet satisfying a third predeterminedcondition, starting to maintain the lifetime of the first automaticretransmission buffer block corresponding to the packet; wherein thethird predetermined condition comprises one of the following: a newlytransmitted packet is indicated in new-transmission indicationinformation carried in the packet or a third predetermined numbercarried in the packet is different from third predetermined numberscarried in packets buffered in all automatic retransmission bufferblocks in an automatic retransmission buffer; or in response to thepacket satisfying a fourth predetermined condition, continuingmaintaining the lifetime of the first automatic retransmission bufferblock corresponding to the packet; wherein the fourth predeterminedcondition comprises one of the following: a retransmitted packet isindicated in new-transmission indication information carried in thepacket or a second automatic retransmission buffer block exists in theautomatic retransmission buffer, wherein a third predetermined numbercarried in a packet buffered in the second automatic retransmissionbuffer block is the same as a third predetermined number carried in thereceived packet; and wherein in response to the packet satisfying thethird predetermined condition, the method further comprises configuringthe lifetime of the first automatic retransmission buffer block for thepacket.
 17. A transmission apparatus, comprising: a processor and amemory storing processor-executable instructions which, when executed bythe processor, are configured to implement the method of claim 14.